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Chronic Fatigue Syndrome

Fatigue is a very common complaint. When the fatigue persists for longer than six months, has no obvious cause and is associated with other complaints such as “mental fogginess,” a vague sense of not feeling well after exertion and unrefreshed sleep, it is referred to as chronic fatigue syndrome (CFS).

CFS has gone by many other names, such as myalgic encephalomyelitis and chronic mononucleosis. It also overlaps with other illnesses such as fibromyalgia, depression and hypothyroidism.

CFS can start suddenly or gradually and last for years, although in adolescents and young adults it usually starts suddenly and either goes away or is much better within a year. CFS affects two to four times more girls than boys; in adolescents and young adults the female preponderance may be even higher.

The cause of CFS has not been identified, nor are there specific tests available to diagnose the condition.

CFS is treated by the specialists in Lurie Children's Division of Infectious Diseases. Learn more.


The following are the most common symptoms of CFS:
  • Impairment in short-term memory or concentration
  • Headache
  • Tender lymph glands (nodes)
  • Fatigue and weakness
  • Muscle pain
  • Joint pain
  • Unrefreshed sleep
  • A vague sense of not feeling well after exertion that lasts more than 24 hours

The symptoms of chronic fatigue syndrome may resemble those of other medical conditions, which must be ruled out prior to making a diagnosis of CFS. Always consult your physician for a diagnosis.


CFS is diagnosed as follows:
  • Severity and duration: The severe and chronic tiredness has to have lasted for more than six months.
  • Ruling out of other medical conditions: Such as depression or hypothyroidism.
  • Number of symptoms: The patient has four or more of the symptoms of CFS listed above.
  • Treatment

A specific treatment for CFS has yet to be proven effective. Medications to relieve symptoms are sometimes useful, but patients with CFS tend to have many side effects from medications, so drugs must be used cautiously and are usually begun in low doses.

Many patients with CFS have lost physical fitness due to the severe fatigue; graded exercise can often help. Improvements in sleep habits can also be of benefit. Encouraging as much pleasant or necessary activity as is tolerable (such as attending school or working), even if only very part-time initially, can also help patients cope or recover.

Finally, cognitive therapy (helping patients gain insight into their condition and develop better coping mechanisms) can also be of great help.