Weakness and Fatigue
Weakness and fatigue are terms that are often used as if they mean the same thing. But in fact they describe two different sensations. It is important to know exactly what you mean when you say "I feel weak" or "I am fatigued" because it can help you and your doctor narrow down the possible causes of your symptoms.
Both weakness and fatigue are symptoms, not diseases. Because these symptoms can be caused by many other health problems, the importance of weakness and fatigue can be determined only when other symptoms are evaluated.
General weakness often occurs after you have done too much activity at one time, such as by taking an extra-long hike. You may feel weak and tired, or your muscles may be sore. These sensations usually go away within a few days.
In rare cases, generalized muscle weakness may be caused by another health problem, such as:
Muscle weakness that is slowly getting worse requires a visit to a doctor.
Sudden muscle weakness and loss of function in one area of the body can indicate a serious problem within the brain (such as a stroke or transient ischemic attack) or spinal cord or with a specific nerve in the body.
Fatigue is a feeling of tiredness, exhaustion, or lack of energy. You may feel mildly fatigued because of overwork, poor sleep, worry, boredom, or lack of exercise. Any illness, such as a cold or the flu, may cause fatigue, which usually goes away as the illness clears up. Most of the time, mild fatigue occurs with a health problem that will improve with home treatment and does not require a visit to a doctor.
A stressful emotional situation may also cause fatigue. This type of fatigue usually clears up when the stress is relieved.
Many prescription and nonprescription medicines can cause weakness or fatigue. The use or abuse of alcohol, caffeine, or illegal drugs can cause fatigue.
A visit to a doctor usually is needed when fatigue occurs along with more serious symptoms, such as increased breathing problems, signs of a serious illness, abnormal bleeding, or unexplained weight loss or gain.
Fatigue that lasts longer than 2 weeks usually requires a visit to a doctor. This type of fatigue may be caused by a more serious health problem, such as:
Chronic fatigue syndrome is an uncommon cause of severe, persistent fatigue.
If fatigue occurs without an obvious cause, it is important to evaluate your mental health. Fatigue is a common symptom of mental health problems, such as anxiety or depression. Fatigue and depression may become so severe that you may consider suicide as a way to end your pain. If you think your fatigue may be caused by a mental health problem, see your doctor.
Check your symptoms to decide if and when you should see a doctor.
eMedicineHealth Medical Reference from Healthwise
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