Chronic fatigue syndrome (CFS) is a debilitating disorder characterized by extreme fatigue or tiredness that does not go away with rest and cannot be explained by an underlying medical condition. CFS may also be called myalgic encephalomyelitis (ME) or systemic stress intolerance disease (SEID).
The causes of chronic fatigue syndrome are not well understood. Some theories include viral infection, psychological stress, or a combination of factors. Because no single cause has been identified, and because many other illnesses produce similar symptoms, CFS can be difficult to diagnose. There are no tests for CFS, so your doctor will have to rule out other causes of your fatigue.
People with chronic fatigue syndrome sometimes have a weakened immune system, but doctors don't know if this is enough to cause illness. Also, people with CFS sometimes have abnormal levels of hormones, but doctors have not yet concluded whether this is significant.
Chronic fatigue syndrome is most common among people between the ages of 40 and 50. Gender also plays an important role in CFS, as women are at least twice as likely to develop CFS as men. Genetic predisposition, allergies, stress, and environmental factors can also increase your risk.
Symptoms of CFS vary depending on the person affected and the severity of the condition. The most common symptom is fatigue, which is severe enough to interfere with your daily activities. For CFS to be diagnosed, fatigue must last for at least six months and must not be curable with bed rest. Also, you must have at least four other symptoms.
Other symptoms of chronic fatigue syndrome can include:
- Loss of memory or concentration.
- Feeling unrested after a night's sleep.
- Chronic insomnia (and other sleep disorders).
- Muscle pain.
- Frequent headaches
- Multiple joint pain without redness or swelling.
- Frequent sore throat
Chronic fatigue syndrome is a very difficult condition to diagnose. According to the Institute of Medicine, CFS occurs in 836,000 to 2.5 million Americans, but an estimated 84 to 91 percent have yet to be diagnosed. There are no laboratory tests to detect CFS, and its symptoms are common to many diseases. Many people with CFS do not seem obviously sick, so doctors may not recognize that they are sick.
