Physical Changes - Aging And Energy: Chronic Fatigue

Content provided by the Faculty of the Harvard Medical School

Physical changes

Aging brings a number of physical changes. The onset of menopause (see "Menopause") creates changes that may cause fatigue. As estrogen levels decline, many women have hot flashes, which can interrupt sleep and even lead to chronic insomnia.

In both men and women, muscle mass declines steadily. By age 70, you've lost 30% of the muscle mass you had at age 20. A drop in muscle mass means a decrease in strength and an increase in fatigue. As muscles shrink, they become fatigued more rapidly. With age, your ligaments and joints become stiffer, so you move more slowly. To a large extent, you can compensate for these changes by exercising regularly to maintain strength and flexibility. Weight training increases muscle strength, and stretching increases flexibility.

Along with a decline in physical energy, many people find that their mental energy falls somewhat as they age. They have a harder time concentrating and remembering things, and it takes longer to learn new information. In part, these difficulties reflect age-related chemical changes in the brain that affect memory and learning. On the bright side, staying active mentally by reading, doing crossword puzzles, and learning new mental skills can help offset this age-related decline.

Illness. Aside from normal age-related changes, illnesses that become more common with age can deplete your energy (see "Other medical conditions"). Many illnesses can interfere with sleep. For example, people with congestive heart failure may awaken feeling short of breath because body fluids accumulate in the lungs while they're lying down. People with heartburn find that their discomfort is greatest when they lie down and stomach acids back up into the esophagus. And hundreds of prescription and over-the-counter drugs can make it harder for you to sleep at night (see "Medications").

Fatigue is also a common symptom of a wide range of diseases, including anemia, kidney disease, multiple sclerosis, diabetes, and cancer. In some cases, such as in cancer, fatigue may be the earliest sign that something is wrong. In others, such as chronic kidney disease, fatigue results from the underlying disease process. In any event, if you suddenly feel listless, it's worth visiting your doctor to make sure nothing serious is wrong.

Last updated:	January 23, 2007