The function of saline is to clear wounds, reduce inflammation, correct dehydration and acidosis. 1. Cleansing, anti-inflammatory: daily skin breaks or abrasions, you can use saline to clean wounds, can reduce local tissue edema, oozing, so as to achieve the effect of cleansing and anti-inflammatory. 2. Correct dehydration and acidosis: when the body has a more serious diarrhea, not only will the body lose sodium bicarbonate and produce metabolic acidosis, but also will make the body appear nutritional disorders, ketosis, and a large number of electrolytes and water loss phenomenon. At this time, you can combine with the physical condition, by the doctor’s guidance can be used to correct dehydration and acidosis and other symptoms. In addition, saline can also be used clinically for other medical purposes, but also commonly used for in vitro culture of living tissue, cells. When saline is made into injection form, too much infusion, too fast, can lead to sodium retention, causing edema, increased blood pressure, increased heart rate, chest tightness, dyspnea, and even acute left heart failure. When used as an injection, it is contraindicated in hypertensive syndrome of pregnancy. When using saline, it needs to be used under the guidance of a doctor and is not recommended to be used blindly.