ACE Inhibitors: What They Are and How They Work

ACE inhibitors are medicines that help relax blood vessels so the heart doesn’t have to work as hard. They block an enzyme called angiotensin‑converting enzyme, which normally tightens blood vessels. By stopping this enzyme, the vessels stay wider, blood pressure drops, and the heart gets relief. If you’ve been told you have high blood pressure, heart failure, or kidney problems, an ACE inhibitor is often one of the first drugs your doctor will suggest.

When to Use ACE Inhibitors

These drugs are most often prescribed for:

• High blood pressure (hypertension)
• Heart failure – especially after a heart attack
• Kidney disease caused by diabetes
• Preventing a second heart attack

Doctors may also use them after a heart attack to improve survival. If you have any of these conditions, ask your doctor whether an ACE inhibitor fits your treatment plan. The most common ones you’ll see on a prescription label are lisinopril, enalapril, ramipril, and benazepril.

Common Side Effects and What to Watch For

Most people tolerate ACE inhibitors well, but a few side effects pop up fairly often. A dry cough is the classic complaint – it can be annoying and sometimes leads doctors to switch medications. You might also feel dizzy, especially after the first few doses, because your blood pressure drops quickly.

Rare but serious reactions include swelling of the face, lips, or tongue (angio‑edema) and a sudden rise in potassium levels. If you notice swelling, trouble breathing, or a fast heartbeat, call a health professional right away.

Kidney function can change, so doctors usually check blood work after you start the drug and then every few months. If you’re on a potassium‑saving diuretic or a supplement, keep an eye on your potassium levels too.

Women who are pregnant should avoid ACE inhibitors because they can harm the baby. If you become pregnant while taking one, talk to your doctor right away for a safer alternative.

Dosage varies by drug and by how badly you need the blood pressure lowered. Your doctor will start you on a low dose and adjust it based on blood pressure readings and any side effects. It’s important to take the medicine at the same time each day, with or without food, to keep a steady level in your system.

Missing a dose? Take it as soon as you remember unless it’s almost time for the next one – then just skip the missed pill and keep your regular schedule. Don’t double up; that can cause low blood pressure and dizziness.

When you’re on an ACE inhibitor, keep a simple log of your blood pressure at home. If the numbers stay high after a few weeks, or if you feel unwell, let your doctor know. Small changes in diet—like reducing salt—can boost the medication’s effect.

Our site has easy‑to‑read guides on specific ACE inhibitors, dosage tables, and how they compare to other blood‑pressure drugs. Browse the related articles for deeper dives into each medicine, tips for safe supplement use, and answers to common patient questions.

Bottom line: ACE inhibitors are a reliable tool for lowering blood pressure and protecting the heart. Knowing the main side effects, staying on top of blood tests, and talking openly with your doctor will help you get the most benefit with the fewest hassles.