Physiological saline refers to the concentration of 0.9% sodium chloride injection, the concentration of 0.9% means 0.9g of sodium chloride dissolved in 100ml of sterilized water for injection, the osmotic pressure of physiological saline is basically equal to the osmotic pressure of human blood, it is an isotonic solution, clinically it is mainly used for the treatment of water loss due to various reasons, as well as hypochloremic metabolic acidosis, in addition, it can also be used as In addition, it can also be used as a topical anti-inflammatory solution, used to flush wounds, flush the eyes or can also be used as a solvent for other drugs during intravenous dripping, when the drug is used must avoid excessive and rapid dripping, otherwise it will have the side effects of increased blood pressure, acute left heart failure, accelerated heart rate, water and sodium retention.