Angiotensin-converting enzyme

Angiotensin-converting enzyme (ACE) is a protein in your body that plays a key role in controlling blood pressure. It helps produce a substance called angiotensin II from another substance, which causes blood vessels to narrow. Narrower blood vessels increase blood pressure, helping ensure your organs get enough blood. ACE is mainly found in the lungs and works as part of a balancing system to regulate blood pressure and fluid levels. Medications called ACE inhibitors can block this enzyme, helping to lower high blood pressure and reduce strain on the heart.