Salt dissolved in water. Various concentrations are used in medicine, including normal saline, which contains 0·9 gm of sodium chloride per 100ml of water. There is also half normal saline, usually given in conjunction with dextrose rather than water as well as other less frequently used solutions. They are used to treat or prevent dehydration when fluids cannot be taken by mouth; as a means of keeping an intravenous infusion site from clotting when drugs are given intermittently through it; to dilute drugs given by injection; and as emergency treatment of blood loss from accident or while awaiting the arrival of PLASMA or blood for TRANSFUSION.

Saline is also given orally to severely dehydrated children or adults suffering from diarrhoea and, in particular, CHOLERA.