Alternate Names : Weariness
Fatigue is a condition in which a person becomes weary or exhausted. It is usually caused by overdoing some physical activity. It can also occur after a long period of mental stress. In some cases, it may occur for no clear reason.
What is going on in the body?
Most people have had fatigue at some point. The causes of fatigue range from working out or studying too hard to cancer. Sometimes no cause can be found.
What are the causes and risks of the condition?
Almost any sudden illness and many long-term illnesses can cause fatigue. The more common causes of fatigue include:
lack of sleep or difficulty sleeping
infections, such as acute bronchitis, mononucleosis and AIDS
a low blood count, or anemia
working, studying or exercising too much
lack of exercise or poor physical conditioning
hormone imbalances, such as hypothyroidism
hormonal changes in women during menopause
chronic fatigue syndrome, in which a person has fatigue for long periods of time for no apparent reason
depression or other psychological disorders, including emotional conflict, anxiety, frustration and boredom
autoimmune disorders, in which a person's immune system attacks his or her own body for no apparent reason
toxin or chemical exposure, such as carbon monoxide or lead poisoning
medications, such as antihistamines, cancer chemotherapy, or certain medications used to treat depression and high blood pressure
heart disease or disorders, including congestive heart failure
lung diseases and disorders, including pulmonary edema and emphysema
kidney disorders, including chronic renal failure
liver disease, including cirrhosis
There may be many other causes of fatigue as well. Sometimes a cause cannot be found.