Fatigue is different from drowsiness. 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 activity, emotional stress, boredom, or lack of sleep. Fatigue is a common symptom, and it is usually not due to a serious disease. But it can 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.
Chronic fatigue syndrome (CFS) is a condition in which symptoms of fatigue persist for at least 6 months and do not resolve with rest. The fatigue may be worsened with physical activity or mental stress. It is diagnosed based on the presence of a specific group of symptoms and after all other possible causes of fatigue are ruled out.
There are many possible causes of fatigue, including:
- Anemia (including iron deficiency anemia)
- Depression or grief
- Iron deficiency (without anemia)
- Medicines such as sedatives or antidepressants
- Persistent pain
- Sleep disorders such as insomnia, obstructive sleep apnea, or narcolepsy
- Thyroid gland that is underactive or overactive
- Use of alcohol or drugs such as cocaine or narcotics, especially with regular use
Fatigue can also occur with the following illnesses:
- Addison disease
- Anorexia nervosa or other eating disorders
- Arthritis, including juvenile rheumatoid arthritis
- Autoimmune diseases such as systemic lupus erythematosus
- 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, hepatitis, human immunodeficiency virus (HIV) AIDS, tuberculosis, and mononucleosis
- Kidney disease
- Liver disease
Certain medicines may also cause drowsiness or fatigue, including antihistamines for allergies, blood pressure medicines, sleeping pills, steroids, and diuretics.
Here are some tips for reducing fatigue:
- Get enough sleep each night.
- Eat a healthy, well-balanced diet and drink plenty of water throughout the day.
- Exercise regularly.
- Learn better ways to relax. Try yoga or meditation.
- Maintain a reasonable work and personal schedule.
- Change or reduce your stressors, if possible. For example, take a vacation or resolve relationship problems.
- Take a multivitamin. Talk to your doctor about what is best for you.
- Avoid alcohol, nicotine, and drug use.