There are three angina types:
Stable angina is the most common angina type. It can also be referred to as exertional angina. With exertion, like walking up a hill or climbing stairs, the heart works harder and needs more oxygen. If it can't get enough oxygen, a person develops symptoms of angina. With rest, the angina attack symptoms generally improve.
Unstable angina is the second most common angina type. This is a dangerous condition that requires emergency treatment. It occurs more often in older adults and is a sign that a heart attack could occur soon. In fact, 10 to 20 percent of people with unstable angina symptoms will likely have a heart attack.
Variant angina is a rare angina type caused by a spasm in a coronary artery. This spasm causes the walls of the artery to tighten. This narrows the artery, causing the blood flow to the heart to slow or stop.
(Click Types of Angina for an in-depth look at these different types, including information on their individual causes, symptoms, and risk factors.)