Hypotonic saline is a solution that contains a lower concentration of salt (sodium chloride) than the fluid inside human cells. This type of saline is often used in medical settings to help hydrate patients or to treat conditions like hyponatremia, where sodium levels in the blood are too low. When administered, it can help shift fluid into cells, promoting cellular hydration. In contrast to isotonic saline, which has the same salt concentration as body fluids, hypotonic saline can cause cells to swell. This property makes it important for healthcare providers to monitor patients closely when using this solution to avoid potential complications, such as cell lysis, where cells may burst due to excessive swelling.