Captopril is used alone or in combination with other medications to treat high blood pressure and heart failure. It is also used to improve survival and reduce the risk of heart failure after a heart attack in patients a heart condition called left ventricular hypertrophy (enlargement of the walls of the left side of the heart). Captopril is also used to treat kidney disease (nephropathy) caused by diabetes in patients with type 1 diabetes and retinopathy (eye disease). Captopril is in a class of medications called angiotensin-converting enzyme (ACE) inhibitors. It decreases certain chemicals that tighten the blood vessels, so blood flows more smoothly and the heart can pump blood more efficiently. High blood pressure is a common condition, and when not treated it can cause damage to the brain, heart, blood vessels, kidneys, and other parts of the body. Damage to these organs may cause heart disease, a heart attack, heart failure, stroke, kidney failure, loss of vision, and other problems. In addition to taking medication, making lifestyle changes will also help to control your blood pressure. These changes include eating a diet that is low in fat and salt, maintaining a healthy weight, exercising at least 30 minutes most days, not smoking, and using alcohol in moderation.