Weakness of legs and easy fatigue may be related to physiological reasons such as lack of exercise and overwork, as well as pathological reasons such as hypokalemia, spinal cervical spondylosis and lumbar disc herniation. 1. Physiological reasons (1) Lack of exercise: If the patient usually lacks exercise, he/she may be weak. If he/she suddenly strengthens his/her activities, such as climbing or running, it may aggravate the phenomenon of weakness and easy fatigue of the legs. (2) overwork: if the patient recently overworked and strenuous exercise, due to muscle metabolism produces a large amount of lactic acid ah, can not be discharged in a timely manner, the accumulation of lactic acid will cause weakness of the legs fatigue and other phenomena, which can be effectively improved through appropriate rest. 2. Pathological causes (1) Hypokalemia: Hypokalemia may be caused by too little potassium intake in daily life, too much potassium discharged through sweat, urine, gastrointestinal tract, etc., or hereditary diseases, etc., which may lead to symptoms such as weakness of legs and easy fatigue. (2) Spinal cord cervical spondylosis: Spinal cord cervical spondylosis is mainly caused by spinal cord injury due to spinal cord compression and ischemia, and in the early stage of the disease, symptoms such as weakness and fatigue of legs may occur. (3) Herniated lumbar discs: Herniated lumbar discs cause nerve roots in the legs to be compressed, which may lead to weakness and fatigue in the legs. Weakness and fatigue of legs may also have other reasons, it is recommended to go to the regular hospital in time, complete the relevant examination, after clarifying the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.