To be diagnosed as
chronic fatigue syndrome, symptoms must last for at least
six months. Unfortunately, in many people, symptoms persist for years. Symptoms tend to be worst in the first
one to two years, and most people's level of functioning gradually improves over time.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.
