Fatigue is a feeling of weariness, tiredness, or lack of energy.
Tiredness; Weariness; Exhaustion; Lethargy
Fatigue is different from
drowsiness. In general, drowsiness is feeling the need to sleep. Fatigue is a lack of energy and motivation. Drowsiness and apathy (a feeling of not caring about what happens) can be symptoms that go along with fatigue.
Fatigue can be a normal and important response to physical exertion, emotional stress, boredom, or lack of sleep. However, it can also be a sign of a more serious mental or physical condition. When fatigue is not relieved by enough sleep, good nutrition, or a low-stress environment, it should be evaluated by your doctor. Fatigue is a common symptom, and it is usually not due to a serious disease.
The pattern of fatigue may help your doctor determine its cause. For example, if you wake up in the morning rested but quickly develop fatigue with activity, you may have a condition such as an underactive thyroid. On the other hand, if you wake up with a low level of energy and have fatigue that lasts throughout the day, you may be
There are many possible causes of fatigue, including:
Anemia(including iron deficiency anemia)
- Medications such as sedatives or antidepressants
- Persistent pain
Sleep disorderssuch as insomnia, obstructive sleep apnea, or narcolepsy
- Thyroid gland that is
- Use of alcohol or drugs such as cocaine or narcotics, especially with regular use
Fatigue can also occur with the following illnesses:
Anorexiaor other eating disorders
- Arthritis, including
juvenile rheumatoid arthritis
- Autoimmune diseases such as systemic
Congestive heart failure
- Infection, especially one that takes a long time to recover from or treat, such as
bacterial endocarditis(infection of the heart muscle or valves), parasitic infections, AIDS, tuberculosis, and mononucleosis
- Kidney disease
- Liver disease
Certain medications may also cause drowsiness or fatigue, including antihistamines for allergies, blood pressure medicines, sleeping pills, steroids, and diuretics.
Chronic fatigue syndrome(CFS) is a condition that starts with flu-like symptoms and lasts for 6 months or more. It is diagnosed after all other possible causes of fatigue are ruled out. Most people with CFS do not get much relief from rest.