Sudden fever, body aches and lack of strength, may be the upper respiratory tract infection, tuberculosis and other diseases, it is best to go to the hospital for examination, to find out the cause of the disease, and then follow the doctor’s instructions for treatment. 1. Upper respiratory tract infection: upper respiratory tract infection will appear high fever state, in the body high fever will lead to muscle cells lactic acid metabolism and thus the phenomenon of generalized pain and weakness. 2. Tuberculosis: Tuberculosis patients with low immunity function, it is easy to appear high fever, at this time if the patient appeared to sweat, loss of more water may lead to electrolyte disorders, thus causing muscle weakness and soreness of the symptoms. Sudden fever body aches and pains without strength may also be other reasons, it is recommended to consult a doctor in a timely manner, so as not to delay treatment.