The weakness and weakness of the legs and nausea may be some kind of adverse physiological reaction of the human body, or may be related to systemic diseases, and in special cases seen in a particular disease. 1. physiological factors, early pregnancy. 2. adverse environmental factors. Hypoglycemic reaction caused by long working hours, lack of rest and lack of energy. Dehydration caused by working in a hot environment, heavy sweating and excessive water loss, after drunkenness. 3. Nutritional metabolic imbalance. Severe diabetes, malnutrition, severe anemia and hemorrhagic shock, etc. 4, late malignant tumor, during radiation and chemotherapy treatment. 5, severe infection. 6, mixed cervical spondylosis.