The causes of limb weakness include lack of sleep, anemia, mental reasons. 1. Lack of sleep: a long time to stay up late, insomnia and other causes of sleep time is too short, will lead to the brain is in a state of tension, the body can not get enough rest, which in turn affects the blood circulation of the body’s organs, so that the organism feel limb weakness, the whole body is weak, no spirit, and so on. 2. Anemia: If dietary imbalance, unreasonable eating habits or gastrointestinal diseases, etc., will lead to insufficient intake of iron, vitamin B, folic acid, etc., resulting in anemia, which can be seen in the weakness of the limbs, general body soreness and other muscle hypoxia manifestations as well as lack of spirit and other manifestations. 3. Mental reasons: daily if the individual mental stress is too large, long-term mental anxiety will lead to the body to appear limb weakness, no spirit of the performance, it is recommended that daily attention to self-regulation, work and rest, relaxation of emotions. If the weakness of the limbs of the body soreness without spirit persists, it is recommended to seek medical attention as soon as possible to clarify the cause of the disease, and give targeted treatment.