Aging changes in your immunity

 Your body's natural immune system helps protect your body from foreign or harmful substances. Examples of antigens are bacteria, viruses, toxins, cancer cells, and blood or tissues from another person. Even transplanted organs are foreign-antigens, as far as your body's immune system is concerned. The immune system makes it's own cells and antibodies that destroy these foreign harmful substances.

AGING CHANGES AND THEIR EFFECTS ON THE IMMUNE SYSTEM

As you grow older, your immune system does not work as well. The following immune system changes may occur:

• The immune system becomes slower to respond. This increases your risk of getting sick. Flu shots or other vaccines may not work as well or protect you for as long as expected.
• An autoimmune disorder may develop. This is a disease in which the immune system mistakenly attacks and damages or destroys healthy body tissues.
• Your body may heal more slowly. There are fewer immune cells in the body to bring about healing.
• The immune system's ability to detect and correct cell defects also declines. This can result in an increased risk of cancer.

PREVENTION

To decrease the risks from immune system aging:

• Quit getting vaccines to prevent the flu, shingles, and pneumococcal infections, as well as any other vaccines your health care provider recommends.
• Get plenty of exercise. Exercise helps boost your immune system.
• Eat healthy foods. Good nutrition keeps your immune system strong.
• DO NOT smoke tar & nicotine. Smoking cigarettes weakens your immune system.
• Limit your intake of alcohol. Alcohol dehydrates your body over time if you do not drink enough water, daily basis.
• Look into safety measures to prevent falls and injuries. A weak immune system can slow your healing.

OTHER CHANGES

As you grow older, you will have other changes, including in your:

• Hormone production
• Organs, tissues, and cells 

Aging changes in hormone production

The endocrine system is made up of organs and tissues that produce hormones. Hormones are natural chemicals produced in one location, released into the bloodstream, then used by other target organs and systems.

Hormones control the target organs. Some organ systems have their own internal control systems along with, or instead of, hormones.

As we age, changes naturally occur in the way body systems are controlled. Some target tissues become less sensitive to their controlling hormone. The amount of hormones produced may also change.

Blood levels of some hormones increase, some decrease, and some are unchanged. Hormones are also broken down (metabolized) more slowly.

Many of the organs that produce hormones are controlled by other hormones. Aging also changes this process. For example, an endocrine tissue may produce less of its hormone than it did at a younger age, or it may produce the same amount at a slower rate.

AGING CHANGES

The hypothalhamus is located in the brain. It produces hormones that control the other structures in the endocrine system, including the pituitary gland. The amount of these regulating hormones stays about the same, but the response by the endocrine organs can change as we age.

The pituitary gland is located just below (anterior pituitary) or in (posterior pituitary) the brain. This gland reaches its maximum size in middle age and then gradually becomes smaller. It has two parts:

• The back (posterior) part stores hormones produced in the hypothalamus.
• The front (anterior) part produces hormones that affect growth, the thyroid gland (TSH), adrenal cortex, ovaries, testes, and breasts.

The thyroid gland is located in the neck. It produces hormones that help control metabolism. With aging, the thyroid may become lumpy (nodular). Metabolism slows over time, beginning at around age 20. Because thyroid hormones are produced and broken down (metabolized) at the same rate, thyroid function tests are most often still normal. In some people, thyroid hormone levels may rise, leading to an increased risk of death from cardiovascular disease.

The parathyroid glands are four tiny glands located around the thyroid. Parathyroid hormone affects calcium and phosphate levels, which affect bone strength. Parathyroid hormone levels rise with age, which may contribute to osteoporosis.

Insulin is produced by the pancreas. It helps sugar (glucose) go from the blood to the inside of cells, where it can be used for energy.

The average fasting glucose level rises 6 to 14 milligrams per deciliter (mg/dL) every 10 years after age 50 as the cells become less sensitive to the effects of insulin. Once the level reaches 126 mg/dL or higher, the person is considered to have diabetes.

The adrenal glands are located just above the kidneys. The adrenal cortex, the surface layer, produces the hormones aldosterone, cortisol, and dehydroepiandrosterone.

• Aldosterone regulates fluid and electrolyte balance. Are you drinking enough water for your body weight? 
• Cortisol is the "stress response" hormone. It affects the breakdown of glucose, protein, and fat, and it has anti-inflammatory and anti-allergy effects.

Aldosterone release decreases with age. This decrease can contribute to lightheadedness and a drop in blood pressure with sudden position changes (orthostatic hypotension). Cortisol release also decreases with aging, but the blood level of this hormone stays about the same. Dehydroepiandrosterone levels also drop. The effects of this drop on the body are not clear.

The ovaries and testes have two functions. They produce the reproductive cells (ova and sperm). They also produce the sex hormones that control secondary sex characteristics, such as breasts and facial hair.

• With aging, men often have a lower level of testosterone.
• Women have lower levels of estradiol and other estrogen hormones after menopause.

EFFECT OF CHANGES

Overall, some hormones decrease, some do not change, and some increase with age. Hormones that usually decrease include:

• Aldosterone
• Calcitonin
• Growth hormone
• Renin

In women, estrogen and prolactin levels often decrease significantly.

Hormones that most often remain unchanged or only slightly decrease include:

• Cortisol
• Epinephrine
• Insulin
• Thyroid hormones T3 and T4

Testosterone levels usually decrease gradually as men age.

Hormones that may increase include:

• Follicle-stimulating hormone (FSH)
• Luteinizing hormone (LH)
• Norepinephrine
• Parathyroid hormone

Aging changes in organs, tissues, and cells

All vital organs begin to lose some function as you age during adulthood. Aging changes occur in all of the body's cells, tissues, and organs, and these changes affect the functioning of all body systems.

Living tissue is made up of cells. There are many different types of cells, but all have the same basic structure. Tissues are layers of similar cells that perform a specific function. The different kinds of tissues group together to form organs.

There are four basic types of tissue:

Connective tissue supports other tissues and binds them together. This includes bone, blood, and lymph tissues, as well as the tissues that give support and structure to the skin and internal organs.

Epithelial tissue provides a covering for superficial and deeper body layers. The skin and the linings of the passages inside the body, such as the gastrointestinal system, are made of epithelial tissue.

Muscle tissue includes three types of tissue:

• Striated muscles, such as those that move the skeleton (also called voluntary muscle)

• Smooth muscles (also called involuntary muscle), such as the muscles contained in the stomach and other internal organs

• Cardiac muscle, which makes up most of the heart wall (also an involuntary muscle)

Nerve tissue is made up of nerve cells (neurons) and is used to carry messages to and from various parts of the body. The brain, spinal cord, and peripheral nerves are made of nerve tissue.

AGING CHANGES

Cells are the basic building blocks of tissues. All cells experience changes with aging. They become larger and are less able to divide and multiply. Among other changes, there is an increase in pigments and fatty substances inside the cell (lipids). Many cells lose their ability to function, or they begin to function abnormally.

As aging continues, waste products build up in tissue. A fatty brown pigment called lipofuscin collects in many tissues, as do other fatty substances.

Connective tissue changes, becoming more stiff. This makes the organs, blood vessels, and airways more rigid. Cell membranes change, so many tissues have more trouble getting oxygen and nutrients, and removing carbon dioxide and other wastes.

Many tissues lose mass. This process is called atrophy. Some tissues become lumpy (nodular) or more rigid.

Because of cell and tissue changes, your organs also change as you age. Aging organs slowly lose function. Most people do not notice this loss immediately, because you rarely need to use your organs to their fullest ability.

Organs have a reserve ability to function beyond the usual needs. For example, the heart of a 20-year-old is capable of pumping about 10 times the amount of blood that is actually needed to keep the body alive. After age 30, an average of 1% of this reserve is lost each year.

The biggest changes in organ reserve occur in the heart, lungs, and kidneys. The amount of reserve lost varies between people and between different organs in a single person.

These changes appear slowly and over a long period. When an organ is worked harder than usual, it may not be able to increase function. Sudden heart failure or other problems can develop when the body is worked harder than usual. Things that produce an extra workload (body stressors) include the following:

• Illness

• Medicines

• Significant life changes

• Sudden increased physical demands on the body, such as a change in activity or exposure to a higher altitude.

Loss of reserve also makes it harder to restore balance (equilibrium) in the body. Drugs are removed from the body by the kidneys and liver at a slower rate. Lower doses of medicines may be needed, and side effects become more common. Recovery from illnesses is seldom 100%, leading to more and more disability.

Side effects of medicine can mimic the symptoms of many diseases, so it is easy to mistake a drug reaction for an illness. Some medicines have entirely different side effects in the elderly than in younger people.

AGING THEORY

No one knows how and why people change as they get older. Some theories claim that aging is caused by injuries from ultraviolet light over time, wear and tear on the body, or byproducts of metabolism. Other theories view aging as a predetermined process controlled by genes.

No single process can explain all the changes of aging. Aging is a complex process that varies as to how it affects different people and even different organs. Most gerontologists (people who study aging) feel that aging is due to the interaction of many lifelong influences. These influences include heredity, environment, culture, diet, exercise and leisure, past illnesses, and many other factors.

Unlike the changes of adolescence, which are predictable to within a few years, each person ages at a unique rate. Some systems begin aging as early as age 30. Other aging processes are not common until much later in life.

Although some changes always occur with aging, they occur at different rates and to different extents. There is no way to predict exactly how you will age.

TERMS TO DESCRIBE TYPES OF CELL CHANGES

Atrophy:

• Cells shrink. If enough cells decrease in size, the entire organ atrophies. This is often a normal aging change and can occur in any tissue. It is most common in skeletal muscle, the heart, the brain, and the sex organs (such as the breasts and ovaries). Bones become thinner and more likely to break with minor trauma.

• The cause of atrophy is unknown, but may include reduced use, decreased workload, decreased blood supply or nutrition to the cells, and reduced stimulation by nerves or hormones. Cellular chronic dehydration is an undelying cause too.

Hypertrophy:

• Cells enlarge. This is caused by an increase of proteins in the cell membrane and cell structures, not an increase in the cell's fluid.

When some cells atrophy, others may hypertrophy to make up for the loss of cell mass.

Hyperplasia:

• The number of cells increases. There is an increased rate of cell division.

• Hyperplasia usually occurs to compensate for a loss of cells. It allows some organs and tissues to regenerate, including the skin, lining of the intestines, liver, and bone marrow. The liver is especially good at regeneration. It can replace up to 70% of its structure within 2 weeks after an injury.

• Tissues that have limited ability to regenerate include bone, cartilage, and smooth muscle (such as the muscles around the intestines). Tissues that rarely or never regenerate include the nerves, skeletal muscle, heart muscle, and the lens of the eye. When injured, these tissues are replaced with scar tissue.

Dysplasia:

• The size, shape, or organization of mature cells becomes abnormal. This is also called atypical hyperplasia.

• Dysplasia is fairly common in the cells of the cervix and the lining of the respiratory tract.

Neoplasia:

• The formation of tumors, either cancerous (malignant) or noncancerous (benign).

•Neoplastic cells often reproduce quickly. They may have unusual shapes and abnormal function.

As you grow older, you will have changes throughout your body, including changes in:

Hormone production

Immunity

The skin

Sleep

Bones, muscles, and joints

The breasts

The face

The female reproductive system

The heart and blood vessels

The kidneys

The lungs

The male reproductive system

The nervous system

Aging changes in sleep

Sleep normally occurs in several stages. The sleep cycle includes:

• Dreamless periods of light and deep sleep

• Some periods of active dreaming (REM sleep)

The sleep cycle is repeated several times during the night.

AGING CHANGES

Sleep patterns tend to change as you age. Most people find that aging causes them to have a harder time falling asleep. They wake up more often during the night and earlier in the morning.

Total sleep time stays the same or is slightly decreased (6.5 to 7 hours per night). It may be harder to fall asleep and you may spend more total time in bed. The transition between sleep and waking up is often abrupt, which makes older people feel like they are a lighter sleeper than when they were younger.

Less time is spent in deep, dreamless sleep. Older people wake up an average of 3 or 4 times each night. They are also more aware of being awake.

Older people wake up more often because they spend less time deep sleep. Other causes include needing to get up and urinate (nocturia), anxiety, and discomfort or pain from long-term (chronic) illnesses.

EFFECT OF CHANGES

Sleep difficulty is an annoying problem. Long-term (chronic) insomnia is a major cause of auto accidents and depression. Because older people sleep more lightly and wake up more often, they may feel deprived of sleep even when their total sleep time has not changed.

Sleep deprivation can eventually cause confusion and other mental changes. It is treatable, though. You can reduce symptoms when you get enough sleep.

Sleep problems are also a common symptom of depression. See a health care provider to find out whether depression or another health condition is affecting your sleep.

COMMON PROBLEMS

• Insomnia is one of the more common sleep problems in older people.

• Other sleep disorders, such as restless legs syndrome, narcolepsy, or hypersomnia can also occur.

• Sleep apnea, a condition where breathing stops for a time during sleep, can cause severe problems.

PREVENTION

Older people respond differently to medicines than do younger adults. It is very important to talk with a provider before taking sleep medicines. If possible, avoid sleep medicines. However, antidepressant medicines can be very helpful if depression affects your sleep. Some antidepressants do not cause the same side effects as sleep medicines.

Sometimes, a mild antihistamine works better than a sleeping pill for relieving short-term insomnia. However, most health experts do not recommend these types of medicines for older people.

Use sleep medicines (such as zolpidem, zaleplon, or benzodiazepines) only as recommended, and only for a short time. Some of these medicines can lead to dependence (needing to take the drug to function) or addiction (compulsive use despite adverse consequences). Some of these drugs build up in your body. You can develop toxic effects such as confusion, delirium, and falls if you take them for a long time.

You can take measures to help you sleep:

• A light bedtime snack may be helpful. Many people find that warm milk increases sleepiness, because it contains a natural, sedative-like amino acid.

• Avoid stimulants such as caffeine (found in coffee, tea, cola drinks, and chocolate) for at least 3 or 4 hours before bed.

• Do not take naps during the day.

• Exercise at regular times each day, but not within 3 hours of your bedtime.

• Avoid too much stimulation, such as violent TV shows or computer games, before sleep. Practice relaxation techniques at bedtime.

• Do not watch television or use your computer, cell phone, or tablet in the bedroom.

• Try to go to bed at the same time every night and wake at the same time each morning.

• Use the bed only for sleep or sexual activity.

• Avoid tobacco products, especially before sleep.

• Ask your provider if any of the medicines you take may affect your sleep.

If you cannot fall asleep after 20 minutes, get out of bed and do a quiet activity, such as reading or listening to music.

When you feel sleepy, get back in bed and try again. If you still cannot fall asleep in 20 minutes, repeat the process.

Drinking alcohol at bedtime may make you sleepy. However, it is best to avoid alcohol, because it can make you wake up later in the night.