Zestoretic 10 is a combination medication used primarily in the treatment of high blood pressure (hypertension). It combines two active ingredients: lisinopril, which is an angiotensin-converting enzyme (ACE) inhibitor, and hydrochlorothiazide, a thiazide diuretic. Lisinopril works by relaxing blood vessels, thereby lowering blood pressure and increasing the supply of blood and oxygen to the heart. Hydrochlorothiazide helps to rid the body of excess salt and water, further helping to reduce blood pressure. Together, these components help to control high blood pressure, reducing the risks of strokes, heart attacks, and kidney problems. Zestoretic 10 is typically prescribed when one medication is not enough to control blood pressure, offering a convenient once-daily dosing option.