The normal level of sodium in human blood is about 135-145 mmol/L. Anything less than 135 mmol/L is called hyponatremia. If it is less than 120mmol/L and is decreasing rapidly, it is a danger sign. Symptoms of hyponatremia include generalized fatigue, apathy, blurred vision, headache, muscle spasms, dyskinesia, nausea, convulsions, and coma to the point of death, and must be treated aggressively. Blood sodium higher than 145 mmol / L is hypernatremia, excessive blood sodium is rare, if the blood sodium is abnormal need to check the urine sodium level for 24 hours, such as excessive urinary sodium, see hypoadrenocorticism, after diuretic treatment and other diseases. Usually pay attention to rest, prevent cold and keep warm, avoid doing strenuous exercise, diet can be appropriate to increase sodium intake, eat more food rich in protein and vitamins, you can eat more fruits and vegetables, avoid eating cold, spicy, cool, stimulating food.