Chronic fatigue syndrome

Chronic fatigue syndrome is a complicated disorder characterized by extreme fatigue that can't be explained by any underlying medical condition. The fatigue may worsen with physical or mental activity, but doesn't improve with rest.

The cause of chronic fatigue syndrome is unknown, although there are many theories — ranging from viral infections to psychological stress. Some experts believe chronic fatigue syndrome might be triggered by a combination of factors.

There's no single test to confirm a diagnosis of chronic fatigue syndrome. You may need a variety of medical tests to rule out other health problems that have similar symptoms. Treatment for chronic fatigue syndrome focuses on symptom relief.

Symptoms Causes Risk factors Complications

Chronic fatigue syndrome has eight official signs and symptoms, plus the central symptom that gives the condition its name:

  • Fatigue
  • Loss of memory or concentration
  • Sore throat
  • Enlarged lymph nodes in your neck or armpits
  • Unexplained muscle pain
  • Pain that moves from one joint to another without swelling or redness
  • Headache of a new type, pattern or severity
  • Unrefreshing sleep
  • Extreme exhaustion lasting more than 24 hours after physical or mental exercise

When to see a doctor

Fatigue can be a symptom of many illnesses, such as infections or psychological disorders. In general, see your doctor if you have persistent or excessive fatigue.

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