Causes of generalized weakness include lack of sleep, excessive exercise, fever caused by pathogen infection, hypokalemia, severe anemia, polymyositis, depression, etc. 1. Lack of sleep at night: when the sleep time is not enough or the quality is not high, the body and the brain can not get enough rest and adjustment, and then there will be a situation that the whole body feels weak, no strength and no spirit during the day. 2. Excessive exercise: Excessive exercise will overdraw the body, resulting in weakness, lack of energy, lack of strength and feeling very tired. 3. Fever triggered by pathogen infection: when the patient has fever, the body is in a state of hypoxia but high exertion, which will cause generalized weakness and tenderness. 4. Hypokalemia: there will be weakness and tenderness of the whole body, or worse, inability to walk, limb paralysis, and even cardiac arrhythmia and respiratory muscle paralysis. 5. Severe anemia: the hemoglobin is too small, the oxygen-carrying capacity decreases, and hypoxia occurs in tissues and organs, which will cause weakness and tenderness of the whole body. 6. Polymyositis: mostly caused by autoimmunity or viral infection, manifested by proximal limb muscle weakness, accompanied by muscle pain and tenderness. 7. Depression: there is often weakness, mental instability, accompanied by depression, irritability and so on. In addition to the above, there are other conditions that may lead to generalized weakness, if the improvement of lifestyle habits, the symptoms did not improve, it is recommended to go to the hospital for an examination, follow the doctor’s instructions in a timely manner for targeted treatment, so as not to delay the course of the disease.