Hydrochlorothiazide is a diuretic medication useful in treating high blood pressure and fluid retention, also known as edema, according to Drugs.com. It prevents the absorption of salt in the body, one of the causes of edema. Doctors often prescribe it to treat congestive heart failure and high blood pressure.
Hydrochlorothiazide is a thiazide diuretic often prescribed to treat edema caused by the use of estrogen or steroids, notes Drugs.com. People with kidney or liver disease, allergies, asthma, diabetes, or gout should not take hydrochlorothiazide. Doctors do not prescribe it for people with glaucoma or for those allergic to penicillin or sulfa drugs.