Vasodilator is a medical term used to describe drugs or substances that relax the smooth muscles in blood vessels, leading to the widening of the blood vessels and increased blood flow. Some common synonyms for vasodilators include blood vessel dilators, artery widenings, and peripheral vasodilators. Other similar terms include nitric oxide donors, calcium channel blockers, and angiotensin receptor blockers, all of which work to relax blood vessels and promote blood flow. Vasodilators are used in the treatment of various medical conditions like hypertension, angina, and heart failure. Some natural vasodilators include garlic, dark chocolate, and fish oils.