If feeling constantly tired despite resting and withdrawing from social life lasts more than 6 months, one can speak of chronic fatigue syndrome.
Symptoms: headache; mental fatigue; inability to focus on work or studies; weakened memory; inattention; sore throat; hair loss; brittle nails; joint and muscle pain; tenderness of the lymph nodes; sleep problems.
Many diseases can cause this syndrome. Infectious and parasitic diseases take a large place among these causes.
