Lisinopril and hydrochlorothiazide are used to treat high blood pressure. Lisinopril is an ACE inhibitor that works by relaxing blood vessels and allowing blood to flow more freely. Hydrochlorothiazide is a water pill diuretic that encourages you to produce more urine, allowing your body to eliminate excess salt and water. Lisinopril Hydrochlorothiazide is used to treat hypertension. Lowering blood pressure aids in the prevention of strokes, heart attacks, and renal disorders. Lisinopril and hydrochlorothiazide may cause side effects dizziness, headache, cough, excessive tiredness, and body pain.