Fatigue is a feeling of weariness, tiredness, or lack of energy.
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 depressed.
There are many possible causes of fatigue, including:
Fatigue can also occur with the following illnesses:
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.
Here are some tips for reducing fatigue:
If you have chronic pain or depression, treating it often helps the fatigue. However, some antidepressant medications may cause or worsen fatigue. Your medication may have to be adjusted to avoid this problem. DO NOT stop or change any medications without first talking to your doctor.
Stimulants (including caffeine) are NOT effective treatments for fatigue. They can actually make the problem worse when the drugs are stopped. Sedatives also tend to worsen fatigue in the long run.
Call your doctor right away if:
Call your doctor if:
Your doctor will perform a complete physical examination, paying special attention to your heart, lymph nodes, thyroid, abdomen, and nervous system. You will be asked questions about your medical history, symptoms, and your lifestyle, habits, and feelings.
Questions may include:
Tests that may be done include the following:
Tiredness; Weariness; Exhaustion; Lethargy
Bennett RM. Fibromyalgia and chronic fatigue syndrome. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007: chap 295.
Griggs RC, Jozefowicz RF, Aminoff MJ. Approach to the patient with neurologic disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007: chap 418.
Robinson JA, Preston DC, Shapiro BE. Proximal, distal, and generalized weakness. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Bradley Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth Heinemann Elsevier; 2008:chap 27.
Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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