Chronic fatigue syndrome (CFS) is defined as astheniathat is from the Greek "asthenes", from a - (without) + sthenos (strength). Indeed, the main complaint of patients with asthenia is "no strength". With this disease, a person loses both physical and mental activity. The main cause of chronic fatigue is considered by some doctors to be prolonged stress on the nervous system, which is experienced by people from developed countries living in overpopulated megacities, as well as a lack of vitamins or minerals.
The main sign of chronic fatigue is a decrease in the energy needed to maintain the vital functions of the body.