1- To correct electrolyte imbalance, promote kidney diuresis, and maintain the tissue or organ perfusion.
2- During shock(except in cardiac shock).
3- Dehydration.
4- Diuresis (Toxicities, renal diseases).
5- After surgical procedure i.e., to prevent hypotension as hypotension may be due to vasodilation, decreased cardiovascular function etc.
6- Acid base imbalance.
7- Electrolyte imbalance.