ACE inhibitors are a class of medications commonly used to treat high blood pressure and heart failure. They work by blocking the action of the enzyme angiotensin-converting enzyme, which helps to relax blood vessels and lower blood pressure. This can improve blood flow and reduce the workload on the heart. These medications can also provide benefits for people with certain kidney conditions and are often prescribed after a heart attack. Common examples of ACE inhibitors include lisinopril, enalapril, and ramipril. While generally well-tolerated, they may cause side effects such as a persistent cough or elevated potassium levels.