ACE: Angiotensin-Converting Enzyme – Definition

Angiotensin-converting enzyme (ACE) is like a tiny machine in your body that helps control how tight your blood vessels are. It changes a substance called angiotensin I into another substance that tells your blood vessels to squeeze. When your vessels squeeze, your blood pressure goes up.

Doctors use medicines called ACE inhibitors to stop this machine from making the squeeze signal. These medicines let your blood vessels relax so blood can flow more easily. That helps lower high blood pressure and protects your heart and kidneys.