Chronic fatigue is a complicated disorder that presents with extreme fatigue (feeling tired most of the time) that may worsen with physical or mental activity, but does not improve with rest. Other symptoms may include loss of memory or concentration, sore throat, unexplained muscle pain, pain that moves from one joint to another, headache, and extreme exhaustion that lasts more than 24 hours after physical or mental exercise.
Chronic fatigue syndrome, or CFS, causes you to feel so tired that you can’t complete normal, daily activities. While chronic fatigue syndrome has no known cause and is difficult to diagnose, its major symptoms can be treated.
The cause of chronic fatigue is unknown. Proposed causes include depression, iron deficiency anemia, low blood sugar, history of allergies, virus infection, dysfunction of the immune system, changes in hormone levels, low blood pressure, autoimmune dysfunction, viral infection, and low blood pressure.