Loop diuretics are used to treat high blood pressure, heart failure, and edema (swelling) due to fluid buildup from kidney, heart, or liver conditions. Loop diuretics work by helping your kidneys remove excess salt and water from your body, which reduces fluid buildup and lowers blood pressure. These medications come in different forms, including oral pills and injections. Examples include furosemide (Lasix), torsemide, and bumetanide (Bumex).