Your immune system helps protect your body from foreign or harmful substances. Examples are bacteria, viruses, toxins, cancer cells, and blood or tissues from another person. The immune system makes cells and something call antibodies that destroy these harmful substances.

Aging Changes and Their Effects on the Immune System

As you grow older, your immune system changes and does not work as well:

• It is slower to respond. This increases 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 destroys healthy body tissues.
• Healing is also slowed in older persons. 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 increase in the risk of cancer.

Prevention

To decrease the risks related to aging and the immune system:

• Get the flu and pneumonia vaccines and any other vaccines recommended by your health care provider.
• Get plenty of exercise. Exercise helps boost your immune system.
• Eat health foods. Good nutrition keeps your immune system strong.
• Do not smoke. Smoking weakens your immune system.
• Limit your intake of alcohol. Ask your health care provider how much alcohol is safe for you.
• Look into safety measures to prevent falls and injuries. A weak immune system can slow healing from falls and injuries.

As You Grow Older, You Will Have Other Changes, Including:

• In hormone production
• In organs, tissues, and cells

Hall WJ, Ahmed B. Pulmonary disorders. In: Duthie EH, Katz PR, Malone ML, eds. Practice of Geriatrics. 4th ed. Philadelphia, PA: Elsevier Mosby; 2007:564.

Minaker KL. Common clinical sequelae of aging. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 24.