The Aging Process: Signs, Effects, and What to Expect as You Get Older

Why Do We Age?

When it comes to aging, one of the few things that scientists agree on is that it happens to everyone. But nobody really knows why we age. Over the course of history, hundreds of theories about human aging have been proposed.

Today, most scientists think that aging is caused by a complex interplay of different factors, including genetics, programmed physiological changes to our cells, and behavioral and environmental influences.

Much of this process is unavoidable. In a sense, our cells are "coded" to die off as time passes. For example, consider the role of telomeres. Telomeres are the protective tips at the end of chromosomes. They're often compared to the plastic tips on shoelaces, and they play a similar role. But over time, telomeres shorten, leaving the genetic material of your chromosomes more vulnerable to unraveling.

As well, when you grow older your cells experience more oxidative stress. That's what happens when free radicals (which are unstable molecules that can damage DNA) aren't balanced by antioxidants in your body. The result is cell damage, which contributes to many of the changes that accompany aging.

Those are just two factors behind the aging process. If you'd like to learn more about the science and theories of growing older, check out these books:

• Borrowed Time: The Science of How and Why We Age by Sue Armstrong
• Lifespan: Why We Age—and Why We Don't Have To by David A. Sinclair
• Cracking the Aging Code: The New Science of Growing Old—And What It Means for Staying Young by Josh Mitteldorf and Dorion Sagan

Why Aging Is a Normal Process (And How to Know When It's Not)

As you've gotten older, you've probably noticed some physical changes such as graying hair or fine wrinkles. Perhaps you've also experienced some cognitive issues, such as occasional forgetfulness, and wondered if you should be worried about dementia. That leads to a common question: How can you tell the difference between normal aging and a medical problem?

That question can be difficult to answer because the range of experiences that different people have as they grow older is almost limitless. If you look at your own circle of friends and relatives, you probably see that everyone ages differently. That can make it tricky to determine what is just normal aging and what may be cause for alarm. So there isn't a simple formula for determining what should happen during the aging process by decade of life because we're all so different.

But here's an important point: Our bodies will definitely change with age, and those changes are nothing to be ashamed of. But it's equally important not to blame all health or mobility problems on growing older. (For example, a senior with a sore knee might decide that his or her knee pain is a normal part of aging. But if the other knee, which is the same age, doesn't hurt, it's definitely possible that something else is going on that isn't related to age.)

In fact, the relationship between age and health problems is more complex than you might realize. Growing older definitely increases the risk for many health issues. But aging isn't necessarily the cause of those issues. For example, consider cancer: According to an article in the American Journal of Preventive Medicine, your risk of being diagnosed with cancer increases with age—until around your 70s. Then it actually starts to decline.

So because health issues can be increasingly complex in the senior years, it's important to have a good relationship with your physician. Be sure to bring up any concerns you have, and don't be afraid to ask questions. Your health is not any less important when you're older.

Here's the bottom line: Any sudden change to your health or unexplained symptom should be investigated right away, no matter how old you are. If you're experiencing pain or discomfort, don't assume it's due to age.

The Effects of Aging

Knowing what to expect as you grow older can help you develop a more positive perspective. After all, you're not just a passive participant in your own aging process. By understanding the physiological and psychological changes of aging, you can play a more active role in protecting your well-being.

Here are some of the changes that can happen to 15 different aspects of your health (and how to deal with them):

1. Skin

Your old photos probably confirm it: Skin changes with age. But it's important to remember that you earned any wrinkles over a lifetime of smiling, laughing, and frowning. In other words, instead of seeing wrinkles as something to be feared, try to see them as reminders that you've lived a life filled with feeling.

Of course, that's always easier said than done, particularly in our youth-obsessed culture. And the multibillion-dollar skincare industry constantly markets the idea of hiding the effects of aging on skin.

Plus, a great deal of research is devoted to studying the science of aging skin. According to skincare experts, the seven signs of aging are fine wrinkles, dull skin, uneven skin tone, dry skin, age spots, rough skin texture, and visible pores.

Fine wrinkles

Elastin and collagen fibers help keep younger skin firm and smooth. But sun exposure and other environmental factors can lead to the breakdown of those fibers. As a result, fine wrinkles form, particularly on the forehead, around the mouth, and at the outer corners of the eyes.

Limiting your sun exposure is one of the best ways to avoid wrinkles. So if you're outside, be sure to wear sunscreen and a sun hat.

As well, you can add a higher risk of wrinkles to the long list of reasons to quit smoking. If you smoke cigarettes, talk to your physician about the most effective ways to quit.

Dullness

Are you wondering what happened to your skin's youthful glow? Simply put, skin constantly sheds old cells and replaces them with newer, brighter skin cells. But as you age, this process slows down. The result is a duller texture to your skin.

To combat that dullness, you should:

• Exfoliate to get rid of the old cells. Look for gentle exfoliating products designed for aging skin.
• Increase the blood flow to your skin in order to encourage new cells to grow. Staying adequately hydrated will increase blood flow. So will exercising, getting enough sleep, and eating a balanced diet.

Uneven skin tone

The coloring of your hair, eyes, and skin is largely due to a pigment called melanin. Some seniors experience an overproduction of melanin, leading to pools of it that are called melasma. The result is blotchier skin, with dark patches and spots.

Diligent use of sunscreen can help prevent melasma. Talk to your doctor about the best treatments for existing patches. Several in-office procedures and many topical treatments can help lessen its effects.

Dry skin

At birth, our bodies are about 75 percent water. But as we age, our bodies lose water, so an elderly body is only about 50 percent water. That's why the effects of aging on the skin include dryness and loss of moisture.

Moisturizers can help keep skin soft and hydrated. And preventing dry skin often starts from the inside, with a diet high in antioxidants and rich in fatty acids.

Age spots

Age spots are small, flat marks that appear after repeated sun exposure. They're sometimes called liver spots (although they don't have anything to do with the liver).

Age spots are usually harmless, but you should bring up any changes in their appearance with your doctor. Laser therapy and cryotherapy can remove them, or they can be lightened with skin-bleaching products.

Rough skin texture

Babies have soft, smooth skin. So why doesn't that silky texture last into the senior years? Several factors come into play. For instance, the dry skin and dead skin cells mentioned above can combine to create an uneven surface. But a good skincare routine centered around moisturizing and exfoliating can help.

Visible pores

As your skin loses elasticity, your pores become more visible when they are clogged with oil or dead skin cells. As well, gravity can "stretch" pores over time. Laser treatments, exfoliation, and pore-minimizing products can reduce their size.

Facial shape

Many of the signs of aging listed above are due to skin damage. But your facial shape can also change. That's because we tend to lose fat in our face. Also, gravity pulls the fat that we do have downwards. As a result, your face changes as you age through the development of more "jowls" around your jawline and more hollows around your eyes.

2. Hearing

Hearing loss is one common result of the aging process. According to the National Institute on Deafness and Other Communication Disorders, about one-third of seniors between the ages of 65 and 74 experience some hearing loss, and almost half of those over 75 do.

The onset of age-related hearing loss, or presbycusis, can be subtle. Seniors often don't experience a sudden drop in hearing ability. Instead, they may gradually find that they're turning up the volume on the TV or radio more often, or more frequently asking relatives to repeat what they've just said.

Why does this happen? Our ears undergo several physical changes that can impact our hearing. As we grow older, the small hair cells of the inner ear can start to break down. Those hair cells "translate" sound into electrical signals for the brain to interpret. With fewer hair cells, this process is less effective.

As well, several conditions that frequently affect seniors can impact their hearing, including:

• Hypertension
• Heart disease
• Diabetes
• History of strokes

Some medications can also lead to hearing issues. And if you have a history of being around loud noises, those sounds may have permanently damaged your ability to hear.

Many people take hearing loss for granted as a normal part of aging. But some of the long-term effects can be serious. In fact, several studies have found a possible link between hearing loss and dementia. As well, poor hearing can impact your long-term health and safety, since you may not hear a doctor's instructions clearly or notice an alarm going off.

So if you notice that sounds are becoming more muffled, or if you can't hear conversations clearly, be sure to talk to your doctor. Although age-related hearing loss can't be reversed, hearing aids and other treatments can help.

Here are some tips to protect your hearing as you grow older:

• Limit your exposure to noisy environments. And if you know you will be around loud noises, consider wearing ear plugs or earmuffs.
• Watch out for wax. If you notice that you have a buildup of ear wax that is muffling your hearing, talk to your doctor about the best way to clean it out. (Don't use cotton swabs, as they can damage your ear drums.)

3. Teeth and Gums

With proper dental care, your teeth can last your lifetime. But seniors are more vulnerable to dental problems, including:

• Gum disease, which can lead to tooth loss
• Dry mouth, which increases the risk of tooth decay and other problems
• Tooth sensitivity, which can make it difficult to eat some foods
• Tooth decay, which can be painful and lead to tooth loss

Why does dental care become more challenging with age? Simple wear and tear is one factor. A lifetime of chewing can break down tooth enamel. As well, because our bodies lose water with age, our mouths become drier, which creates an environment that can lead to tooth decay. And gums start to recede, which leads the softer, more vulnerable root of a tooth exposed.

It all adds up to increased odds of losing teeth. (In fact, about 20 percent of Americans over the age of 65 don't have any teeth at all.) Missing teeth can lead to other health problems, since it becomes more difficult to chew food.

Also, new research suggests a link between gum disease and serious health problems such as diabetes and heart disease. Since seniors already face a higher risk for many of these issues, it's increasingly important to keep an eye on your oral health as you grow older.

Here are some steps to protect your teeth and gums:

• Make dental care a habit. Diligent brushing and flossing is a must for seniors.
• If you have problems with dry mouth, try sucking on sugarless candies or chewing sugarless gum. Also, make sure you stay hydrated and avoid alcohol and cigarettes. Artificial saliva, moisturizing sprays, and similar products can also provide relief.
• Investigate low-cost dental care options. Many seniors lose access to affordable dental insurance after they retire. Because of rising dental costs, those seniors often stop seeing a dentist. But if you're an older adult, dental checkups are more important now than they've ever been. So check out low-cost ways to pay for dental care.

4. Digestive System

Digesting food is a complex process that requires the coordination of several different organs. So perhaps it's not surprising that seniors can face a few changes to their digestive systems. Some possible problems include:

• Difficulty swallowing: As with other organs, movement in the esophagus tends to slow down with age. That can make swallowing difficult. Some medical conditions (including dental problems) that are common among seniors can also lead to swallowing issues.
• Gastroesophageal reflux disease (GERD): The burning sensation that characterizes GERD occurs when the contents of the stomach regurgitate into the esophagus. Many medications commonly taken by seniors list GERD as a possible side effect.
  
  But GERD isn't just an annoyance; serious complications, such as bleeding and scarring, can result. And elderly people are more likely to experience the complications from GERD than younger people.
• Constipation: Bowel movements change with age because the movement of the lower intestine weakens and slows down. That's a big reason why many older adults struggle with constipation. But there are other possible causes of constipation:
  • On average, older people tend to get less physical activity.
  • Many drugs can contribute to constipation.
  • Seniors are more likely to experience dehydration, which can be a factor in constipation.
• Diverticulosis and diverticulitis: These two related conditions are more common for seniors. In fact, about two-thirds of Americans over the age of 85 have diverticulosis, which develops when small pockets or pouches form in the colon. Diverticulitis occurs when those pockets become inflamed. Serious complications can arise from diverticulitis.

How can seniors keep their digestive systems functioning smoothly? Here are some tips:

• Eat a healthy diet. In particular, make sure your diet contains enough fiber (about 21 grams a day for women and 30 grams a day for men). Fresh fruit and vegetables, beans, and whole grains are all excellent sources of fiber.
• Move daily. Exercise will stimulate blood flow to your digestive system.
• Drink enough water. Staying hydrated reduces the risk of constipation.
• Watch your stress levels. When you experience stress, the amount of gastric acid in your gut can rise, which can increase the risk of heartburn.
• Treat any sleep problems. Research in Sleep suggests a link between insomnia and gastrointestinal problems. Plus, being well rested makes it easier to exercise, eat well, and stay relaxed.

5. Bladder and Urinary Tract

Urination is another process that many of us take for granted through most of our lives. But, like digestion, the process of urinating requires the orchestration of several body parts. When one of those parts experiences difficulties, the results can include:

• Difficulty emptying the bladder completely
• Incontinence
• Increased risk of a urinary tract infection (UTI)

Urinary problems are more common in older people. That's partly because the muscular bladder wall tissue becomes weaker and less elastic. These changes make it more difficult for the bladder to contract, which is necessary in order to pee.

In older females, aging-related body changes include the muscles supporting the bladder becoming weaker. That can lead to bladder prolapse (in which the bladder drops into the vagina). And when estrogen levels start to decline, the walls of the urethra become thinner and lose strength. That means the urinary sphincter can't close as tightly. The result? An increased risk of incontinence.

Men also experience urinary problems with age. In fact, older males are more likely to be hospitalized for UTI complications than older women.

Many treatments are available for urinary issues. If you experience any of the symptoms below, talk to your doctor. Incontinence and other bladder issues do not have to be accepted as a normal part of aging.

• Feeling that you must pee immediately
• Having more "accidents"
• More frequent urination
• Difficulty emptying your bladder
• Blood in your urine

6. Kidneys

The National Kidney Foundation says that more than half of seniors over the age of 75 may have kidney disease. And kidney disease is responsible for more deaths annually than breast and prostate cancer.

So why are older adults more vulnerable to kidney disease? The short explanation is that kidneys become smaller and less efficient with age. This decline in efficiency is partly because the arteries supplying blood to the kidneys shrink over time. (Interestingly, these changes do not occur with all adults. Researchers are working to discover the other factors that may be involved with declining kidney functions.)

The symptoms of kidney disease can be sneaky and often aren't recognized until the disease is quite advanced. Simple blood tests can help measure your kidney function, so if you notice any of the following symptoms, mention them to your doctor:

• Puffy eyes, especially in the morning
• Unexplained itchy skin
• Unusual fatigue and difficulty focusing
• Muscle cramps at night
• Reduced appetite
• Unexplained swelling in your feet or ankles

7. Lungs

If you experience sudden difficulties breathing, see a doctor as soon as possible. It could be a sign of lung disease, not normal changes from growing older.

If you don't look after your respiratory health, you could feel breathless more often in your senior years. Consider this: Your lung function starts to decline around the age of 35, and by age 65, you've lost about a liter of lung capacity. Because lungs typically have a peak capacity of about six liters, that's a pretty big reduction.

That decline isn't just due to the aging process in your lungs themselves, but also changes to other parts of your body that support the respiratory system. Here are some of the changes that can affect your breathing:

• Osteoporosis can thin bones and lead to posture changes (including a smaller ribcage) that make it more difficult for your chest to expand.
• The diaphragm muscle weakens, which can make it more difficult to take a deep breath.
• Your immune system can become less effective, so you are more vulnerable to respiratory infections.
• The alveoli (small air sacs in your lungs) stretch out and become less efficient.
• Your airways and blood vessels stiffen.

How can you protect your lungs? A few simple lifestyle habits can make a big difference:

• Breath clean air. Avoid indoor and outdoor pollution. That includes secondhand smoke. And it goes without saying that the best thing you can do for your lungs is to avoid smoking cigarettes.
• Exercise. Not only can cardiovascular exercise improve your lung function, but upper-body strength exercises can improve your posture and make breathing easier.
• Make sure your vaccinations are up to date. In particular, receiving an annual flu shot can help prevent damage from respiratory infections.
• Move around. In addition to formal exercise, simple everyday movement is important. If you sit still or lie in bed for long periods, mucus can accumulate in your lungs.
• Eat more fruit. Research in the European Respiratory Journal points to a relationship between a diet with plenty of fresh fruit (and other antioxidant-rich foods) and healthy lung function.

8. Cardiovascular System

Seniors often worry about their cardiovascular health. And with good reason: Almost half of all adults in America have at least one problem with their heart or blood vessels.

Some possible age-related cardiovascular changes include:

• Your heart wall can thicken. An enlarged heart can result in getting less blood to it, which can make it less efficient—thereby raising your risk of heart failure.
• The walls of your large arteries thicken and become harder. This process, called arteriosclerosis, can lead to high blood pressure (hypertension). High blood pressure can lead to strokes, as well as vision, kidney, and other health issues.
• Plaque can build up on the inside walls of your arteries. That leads to reduced blood flow to the heart.
• The electrical system controlling your heartbeat can become less reliable. That can result in an erratic heartbeat or arrhythmias.
• The valves that control the blood going in and out of your heart can stiffen. As a result, your heart has to work harder.

Unlike some other symptoms of aging, it can take a while to realize the effects of growing older on your heart. That's because the symptoms of heart disease can be hard to notice at first.

So it's important to tell your doctor right away if you experience any of the symptoms listed below:

• An irregular or fluttering heartbeat
• Swollen ankles, feet, belly, or neck
• Chest pain with activity
• Dizziness or feeling lightheaded
• Unusual fatigue
• Unexplained nausea or vomiting
• Feeling short of breath during activities, while at rest, or while lying down
• Difficulties keeping up with regular activities or keeping up with your peers

Some cardiovascular problems typically don't cause any symptoms (but can still wreak havoc on your health). So be sure to maintain a schedule of regular checkups. Your doctor should be monitoring your blood pressure, cholesterol levels, and blood sugar.

As well, it's important to know the warning signs of a heart attack or stroke. Cardiovascular events don't always happen like they do in movies, especially for females. So familiarize yourself with the warning signs.

A healthy lifestyle can go a long way toward preventing heart problems. In the senior years, it's particularly important to:

• Get some moderate exercise. Not only can exercise protect your heart from future damage, it can even reverse the effects of aging. And you don't have to run marathons in order to reap the benefits. The key is consistency. Talk to your doctor about the best exercises for you and aim for about 150 minutes of activity a week.
• Reduce the stress in your life. Yes, it can be hard to avoid stress. But mindfulness activities such as yoga and meditation can reduce its harmful effects.
• Eat right for heart health. A nutritious diet with an emphasis on whole foods, fiber, and healthy fats can help keep your cholesterol, blood sugar, and blood pressure under control.
• Investigate snoring issues. The effects of snoring can lead to more than just a sleepless night for your partner. According to a study in the International Journal of Cardiology, people with cardiovascular risk factors who snore have higher mortality rates than people with risk factors who don't snore.
• If you smoke cigarettes, stop. Seniors who have smoked for many years sometimes feel that the damage from smoking has already been done, so there's no point in stopping. But it's never too late to experience the health benefits of quitting. Talk to your doctor about the best approach for you.

9. Reproductive System

In both men and women, the reproductive system undergoes several changes as time passes. But it's important to realize that a healthy sex life is possible at any age. In fact, some older women find it liberating to not have to worry about pregnancy anymore, and that sense of freedom can lead to better sex. And seniors of both genders often discover that the increased self-knowledge and experience that comes with age can lead to more open and fulfilling sexual relationships, despite any physical changes due to the aging process.

Still, it can take some effort to adjust to age-related hormonal changes. Being aware of what is happening and accepting your aging body without judgment can be a healthy way to adapt.

Men can experience lower sex drive as they get older due to declining testosterone levels. Some males have difficulty with full or partial erectile dysfunction (ED). But these issues aren't always caused by age-related physiological changes. Sometimes other factors come into play, such as stress, relationship difficulties, or medication side effects. So, bring up any sexual difficulties with your doctor.

For women, the hormonal changes that lead to menopause can cause sexual changes, including:

• Thinning of the vaginal walls (which can lead to painful intercourse)
• Vaginal dryness
• Reduced sexual desire

Fortunately, many solutions are available for both genders. Open communication with your doctor is the best starting point for issues connected to the effects of aging on the reproductive system. After all, many people experience similar things, so don't be embarrassed or ashamed. This can be reassuring if you're single and wondering how you can start dating with ongoing health issues.

Men should also remember that their ability to reproduce doesn't decline dramatically with age. Although sperm production can slow down, many older men are able to father children. So males with female partners who have not yet completed menopause should ensure that they use a reliable form of birth control if they want to prevent pregnancies from occurring.

It's also important to be aware that seniors can still contract sexually transmitted infections (STIs). In fact, because their immune systems are often weaker, seniors who engage in risky behavior may be more vulnerable to STIs than younger people. Infection rates are rising for seniors, so be sure to protect yourself and your partner by practicing safe sex until you are certain that both of you do not have any STIs.

10. Body Composition

Many seniors notice that even if their weight remains constant, their body shape changes with age. Perhaps they feel less "firm" than they used to, or maybe they notice that more body fat migrates to their bellies. Frustratingly, these changes can occur even without changes to their diet and exercise routines.

What's going on? Simply put, many seniors experience sarcopenia, or muscle loss, unless they actively work to maintain their muscle tone. According to a study in Clinical Interventions in Aging, the effects of aging on muscles can start as young as 30 and accelerate with age. As a result, we lose about 30 to 50 percent of our muscle strength between the ages of 30 and 80.

Because muscle burns more calories than fat, losing this muscle can lead to a slower metabolism. And a slower metabolism can lead to fat accumulation.

Fortunately, we can do a lot to improve our body composition. For example, seniors of all ages experience positive results from strength training and yoga.

Here's the key point: You're never too old to start building strength. If you're not sure where to start, talk to your doctor. And check out the guide on exercise and physical activity from the National Institute on Aging.

Another change to body composition is the loss of bone mass with age. This process is called osteopenia, which can progress to osteoporosis or loss of bone density.

Due to the effects of aging on their bones, seniors are at a higher risk for fractures. That's a big reason why a seemingly simple fall can have serious health consequences for an older person.

As well, many seniors discover that they are a bit shorter than they used to be. On average, men lose about five centimeters by the age of 80, and women lose about eight, according to research in the American Journal of Epidemiology.

Why do you shrink as you age? It happens partly due to bone loss and partly because the discs between the vertebrae in the spine flatten over time. As well, when we lose muscle mass in the torso, we can develop a more stooped posture that makes us appear shorter. (Exercises that focus on posture can often help restore a bit of height.)

Although losing a few inches may not seem very significant, several studies tie height loss to increased health risks. For example, a study in the Journal of Bone and Mineral Research found that seniors who experience a rapid reduction in height are more likely to fracture a hip.

So how can you protect your bones? Here are some important steps to take:

• Exercise. One interesting study in Gerontology found that people who exercise regularly lose less height than those who aren't active. Both weight-bearing exercise (like walking or dancing) and resistance exercises (like weightlifting) can help maintain bone density.
• Get enough vitamin D and calcium. Consult your doctor or a registered dietitian to find out how much is appropriate for you. Foods rich in calcium include leafy greens, yogurt, and tofu. Good sources of vitamin D include mushrooms, eggs, fatty fish, and fortified drinks and cereals. (Your body does make vitamin D naturally from the sun, but that process becomes less efficient with age.)
• Watch your exposure to harmful substances. Both cigarette smoke and alcohol can negatively impact your bone density.
• Talk to your doctor about your prescriptions. Some medications can increase the likelihood that you will develop osteoporosis. However, medications that work to increase bone density are available.

11. Joints and Connective Tissues

Are sore knees and backs inevitable as we grow older? Not necessarily. In fact, age may not always be to blame for our aching bodies. When it comes to painful joints, scientists now think that inactivity may be a bigger factor than chronological age. Still, many people notice a change in their ease of movement as they get older.

What happens to our joints? When we're young, cartilage and synovial fluid provide protective cushioning at the points where bones meet each other. But with age, both synovial fluid and cartilage start to thin. At the same time, the ligaments that hold our muscles together stiffen.

We also get stiff as we age because our connective tissues (ligaments and tendons) tighten, partly because our bodies lose water. That leads to a decrease in the range of motion in our joints.

Perhaps paradoxically, the best way to avoid stiff, painful movement is to keep moving. Activity will prevent cartilage from stiffening and keep synovial fluid circulating.

Our natural tendency is often to stop moving when we experience pain. Of course, it is important to rest. But seniors can enter into a cycle in which the resulting inactivity leads to even more stiffness and pain.

So if you experience pain, stiffness, redness, and tenderness at any of your joints, or in your lower back, it's important to see a doctor right away. Then you can work together to create a plan that will encourage healthy movement and integrate some stretching to keep your joints limber. Focus on the fact that joint pain is not part of the aging process and find ways to stay active.

12. Immune system

As you get older, your immune system starts to slow down and become weaker. The medical term for this process is immunosenescence.

But why do older seniors have weaker immune systems—at a time in their lives when they could benefit from more protection from illnesses? Here's a short explanation: Your immune system fights germs and other threats to well-being with T cells. As you age, your immune system has fewer of these protective cells. Also, the rate at which you produce antibodies in order to fight infections slows down.

These changes to your immune system can be experienced in several ways:

• You may notice you catch colds and flus more easily than you used to.
• It might take longer to recover from being sick.
• You become more vulnerable to autoimmune disorders such as rheumatoid arthritis or multiple sclerosis.

The steps you can take to boost your immune system as a senior are the same as for improving immunity at any age:

• Make sure your vaccines are up to date.
• Eat a well-rounded diet, with an emphasis on whole foods and plenty of fresh produce.
• Don't smoke.
• Avoid stress and get adequate rest.
• Engage in moderate exercise.

13. Sleep

According to an article in Sleep Medicine Clinics, about 50 percent of elderly adults say that they have problems with sleep. And studies confirm that many older adults simply aren't getting enough. In particular, seniors tend to have more fragmented sleeping patterns, marked by difficulties staying asleep and problems falling back to sleep after waking.

That's unfortunate because it's a myth that seniors need less sleep than younger people. In fact, some researchers say that getting enough sleep is just as vital to healthy aging as getting enough exercise and eating well. That's because being short on sleep can activate the cellular processes linked to aging.

The Population Reference Bureau (PRB) says some studies have even found that regularly sleeping less than six hours a night can lead to brain changes linked to dementia. Poor sleep is also linked to an increased risk of depression.

Seniors can experience many conditions that disturb their sleep. For example, the pain of arthritis can make it difficult to get comfortable in bed. And sleep disturbance is a common side effect of many medications. As well, some older adults find that the new routines of retirement can affect their sleep schedules.

How can you get a good night of sleep that will support healthy aging? Try following these tips:

• If you share a bed with a partner, try to coordinate your sleep schedules and resolve conflicts before bed. PRB says sleep researchers have found that couples with different sleep schedules are less satisfied with their sleep than couples who go to bed and get up at the same times. And members of happy partnerships are more satisfied with their sleep than those who are experiencing relationship difficulties but continue to sleep together.
• Don't drink before you go to bed. Drinking any substance can interfere with sleep if you have to get up to pee. In particular, you should avoid alcohol and caffeine. (Alcohol may initially help you fall asleep, but it often leads to restless, disturbed sleep.)
• Adjust your environment. For many people, an ideal sleep environment is quiet, dark, and cool. (If you have trouble creating a quiet setting for sleep, try a white noise machine to mask sounds.) And make sure you take appropriate fall prevention steps in your bedroom, since seniors can experience falls when they get up at night.
• Create a sleep-friendly lifestyle. We expect a good night's sleep to keep us energized throughout the day. But putting some thought into the day's activities can also make it easier to sleep. For example, regular exercise can help you fall asleep. (For best results, try to fit your workouts in at least three hours before bedtime.) As well, sleep researchers say that maintaining a regular sleep schedule is best. So try to go to sleep and wake up at about the same time every day (even on weekends).

14. Brain and Nervous System

Contrary to what you may have heard, the effects of aging on the brain do not necessarily lead to a fast mental decline when we enter our senior years. The reality is far more nuanced and reflects the "plasticity" of our entire nervous system.

In fact, the most striking aspect of the effects of the aging process on the nervous system is how much it varies from person to person. Many seniors remain bright and engaged well into their 90s, while others experience a decline in cognitive function much earlier.

So, what's normal? Some changes to your cognitive abilities are to be expected. For example, you might pause when introducing someone because you can't remember his or her name. Or you might walk into a room and forget why you wanted to go there. Those types of changes normally occur in memory with age. Although they can definitely be frustrating, they're not necessarily a cause for concern.

However, many seniors worry if they start to forget things regularly. That's because they're concerned about developing dementia.

Here's an important point: On its own, aging does not cause dementia, although it is one of many risk factors. Dementia is not a normal part of aging.

Memory and our ability to learn new things can slow down a bit because aging affects the brain in the following ways:

• The hippocampus shrinks. This can affect the way that we form and retrieve memories.
• The hormones that lead to the growth of neurons and the repair of brain cells start to decline.
• Blood flow to the brain slows down, which can lead to memory and cognition problems.

So the cognitive changes that are seen in the normal aging process include some declining memory functions. But in normal aging, they don't decline enough to affect daily life beyond being inconvenient and possibly embarrassing.

So keep this in mind: Forgetting where you left your keys is normal. But not remembering that you need car keys in order to drive is not normal. In general, the main difference between dementia and normal aging is that dementia-related memory loss affects your day-to-day functioning in a fundamental and negative way.

If you experience changes to your memory and reasoning skills that affect your daily life, talk to your doctor. Her or she can help you determine the cause of those changes.

It's also reassuring to know that when it comes to brain health, the effects of aging are not all negative. Here are some positive developments that many seniors experience:

• Seniors are more likely to focus on the good in a situation. According to the American Psychological Association, research has found that older brains respond more to positive images (and are more likely to remember them) than younger brains.
• Seniors tend to be more optimistic than younger people. This makes sense if you consider that older people can draw from a lifetime of experiences that may have taught them to take a long-term perspective. And because the senior years are often marked by inescapable loss as older adults experience the death of friends and loved ones, our tendency to protect an optimistic view of life may have developed as a way to cope.
• We get better at "big picture" thinking. As we grow older, dendrites (the branches of neurons) start to make more connections between different areas of the brain. According to Harvard Health Publishing, that can make it easier to see relationships between diverse issues.
• Our brains can continue to grow neurons throughout our lives. But that process carries an important caveat: We really do need to "use it or lose it" because this continuing ability relies on our brains remaining active. In other words, learning new things and stimulating our brains becomes even more important as we age.

Some of the other age-related changes to the nervous system involve the spine. As the discs between the vertebrae compress, the function of the nerves along the spinal cord can be damaged. That can lead to balance and coordination problems.

You can take these steps to help protect the functions of your brain and nervous system:

• Focus on brain health when planning your meals. Omega-3 and omega-6 fatty acids have been linked to healthy brain aging. Good sources of omega-3 include:
  • Chia seeds
  • Egg yolks
  • Fatty fish
  • Ground flax seeds
  • Walnuts
  
  And good sources of omega-6 fatty acids include:
  • Pumpkin seeds
  • Sunflower seeds
  • Soybean oil
  • Sunflower oil
  • Safflower oil
• Stay mentally active and continue to challenge yourself. Complex new activities that encourage problem-solving are good for the development of new neurons. That may explain why a study from The Center on Aging, Health & Humanities at The George Washington University has found that seniors enrolled in arts classes seem to age more slowly than peers who don't participate in creative activities.
• Protect your head. Even fairly minor head injuries can affect cognitive function.
• Nurture your social relationships. Growing evidence suggests that regular social activities can help protect our brain health.

Exciting research continues to take place in the field of neuroscience and aging. To learn more, check out books on the subject, such as Brain Rules for Aging Well: 10 Principles for Staying Vital, Happy, and Sharp by John Medina.

15. Vision

For some adults, the first sign of old age is when they're unable to read a restaurant menu. And there's no denying that the likelihood of vision problems increases with age. But with proper care, most age-related vision problems can be managed, so vision issues don't have to affect your quality of life.

Early detection is an important part of preventing vision problems. So seniors should make sure to schedule regular eye exams. After the age of 50, be sure to request a dilated eye exam. The exam can help eye doctors spot potential problems before other symptoms appear.

Some vision issues that are more common as you grow older include:

• Presbyopia: If you have to hold things further away in order to see them clearly, you probably have presbyopia. It's a normal part of the aging process in your eyes and happens because the lens inside your eye hardens and thickens with age.
• Age-related macular degeneration (AMD): The macula is the part of the eye that helps you see straight ahead. When it starts to decay, you may notice blurry spots in the center of your field of vision. As AMD progresses, you may develop blank spots near the center of your vision. As well, the brightness of objects may weaken.
• Cataracts: The lens of an eye is composed of water and protein. With age, the protein can start to form clumps on the lens. The result can be cloudy vision and difficulty distinguishing colors. Although you can develop cataracts in middle age, they are more common in seniors.
• Glaucoma: Glaucoma is actually an umbrella term for many diseases that affect the optic nerve. Often, one of the first signs is difficulty with side vision. Although it can't be entirely cured, early treatment can reduce the impact on your vision. Regular eye exams can help reduce the effects of glaucoma on your vision. And that's important, because glaucoma is the second-leading cause of blindness.

Some lifestyle choices that can help reduce the impact of age-related vision changes include wearing sunglasses when outdoors, resting your eyes when looking at a computer screen for a long time, and eating foods that are known to help with eye health, such as leafy greens, fatty fish, and fresh fruits.

Health Span vs. Life Span

The science of aging is filled with paradoxes. For example, as we've extended the average life span, many illnesses, including Alzheimer's disease, have become more common. In fact, about 85 percent of seniors have a chronic health condition that can impact their quality of life.

So although we're living longer (on average), we're not necessarily living healthier. That's why many seniors choose to focus on their "health span" instead of their "life span." Health span is often considered to be a measure of how long a senior can function independently, without a debilitating chronic condition. For many older Americans, successful aging is the ability to extend their health span and enjoy life comfortably in an environment they choose.

That's why as we grow older, the choices we make regarding our lifestyle become even more important. Although much of the aging process is out of our control, many choices we face can lead to a more fulfilling health span.

As well, geriatric researchers talk about an "aging paradox." That's the phenomenon in which people are more likely to rate their health as "good" when they get older—even if their health has actually gotten worse. Some of this dynamic might be the result of older people comparing themselves to their frailer peers. And some of it might be due to the stereotypes that many people have about aging.

In other words, because society tends to label "old age" as a time of sickness and frailty, many people are surprised to discover that they're still thriving and enjoying life.

Why Different People Age Differently

As you can see, many things change as you grow older. And a lot of those things can vary from person to person. But why is there so much variation? And how much can you control your own aging process?

Scientists believe that about 25 percent of how we age is due to genetic factors. However, environmental and genetic factors are intricately intertwined, so it's difficult to come up with an exact formula for determining how an individual person will age. So although you can look to your parents if you're wondering what to expect at 70 years old and beyond, there are no guarantees. The aging process is unique to each individual precisely because so many different factors are involved.

Still, we can do many things to improve our odds of experiencing good health during our senior years. Although you can't change the genes you are born with, you can make choices that affect how your genes react to the aging process.

While learning how aging can affect different aspects of your body, you've probably noticed some common themes when it comes to protecting your health. That's because the various parts of our bodies work together as a whole unit. What helps one aspect of our health is usually good for other aspects.

So regardless of your age and health concerns, eating well, getting moderate exercise, abstaining from smoking, and dealing effectively with stress can help you cope with physical changes. With aging, it's important to act on the things you can control.

(Some lucky people seem to thrive in old age despite not following medical advice on living a healthy lifestyle. But public health research focuses on the big picture—what, on average, will benefit a person's health. It's usually better to follow that advice than to focus on the experiences of statistical outliers.)

One important factor that is often overlooked is the importance of your attitude toward growing older. Your feelings about aging can actually shape how you age. A study in The Journals of Gerontology: Series B found that older adults did worse on tests that measured things like memory and gait after they were exposed to words that reinforced negative stereotypes about aging.

And in a study in the Journal of Personality and Social Psychology, participating seniors with the most negative attitudes about aging died an average of 7.5 years before the participants with the most positive attitudes.

In other words, although some of the aging process is ultimately out of your control, making healthy lifestyle changes and keeping a positive attitude can go a long way toward helping you enjoy and extend your senior years.

Take Control of Your Future

By knowing what to expect when it comes to the aging process, you can take the right steps to maximize your well-being. Growing older involves many changes. But knowledge and a positive attitude can ensure that you're ready to meet the challenges and extend your "health span."