生理食盐水，生理学或临床上常用的渗透压与动物或人体血浆相等的氯化钠溶液，其浓度用于两栖类时是0.67～0.70％，用于哺乳类和人体时是0.85～0.90％。

医学上，生理盐水（也称作盐溶液）指的是消毒过的氯化钠（NaCl, 更常见的称法是盐水）溶液。但其只有使用静脉注射的时候才是无菌的，其他方式生理盐水也只是一种盐水溶液。这种无菌的溶液一般用于静脉注射，冲洗隐形眼镜和鼻腔冲洗。不同用途的配方中生理盐水也有不同的使用目的。生理盐水也在细胞生物学、分子生物学和生物化学实验中使用。

In medicine, saline (also saline solution) is a solution of sodium chloride (NaCl, table salt) in water. It is used to flush wounds and skin abrasions, as eye drops, for intravenous infusion, rinsing contact lenses, nasal irrigation, and a variety of other purposes. Concentrations of salt vary from low to normal to high. High concentrations are used rarely in medicine but frequently in molecular biology. For parenteral (intravenous) application and tissue irrigation, most commonly used is sterile normal saline, containing 9.0 g of salt per liter (0.90%).