Unstable angina is a condition in which your heart doesn't get enough blood flow and oxygen. It may lead up to a heart attack.

Angina is a type of chest discomfort caused by poor blood flow through the blood vessels (coronary vessels) of the heart muscle (myocardium).

See also:

• Stable angina
• Variant angina

Accelerating angina; New-onset angina; Angina - unstable; Progressive angina

Coronary artery disease due to atherosclerosis is by far the most common cause of unstable angina. Atherosclerosis is the buildup of fatty material called plaque along the walls of the arteries. This causes arteries to become narrowed and less flexible, which interrupts blood flow to the heart, causing chest pain.

People with unstable angina are at increased risk of having a heart attack.

Coronary artery spasm is a rare cause of angina.

Risk factors for coronary artery disease include:

• Diabetes
• Family history of early coronary heart disease -- a close relative such as a sibling or parent had heart disease before age 55 (in a man) or before age 65 (in a woman)
• High blood pressure
• High LDL cholesterol
• Low HDL cholesterol
• Male gender
• Not getting enough exercise
• Obesity
• Older age
• Smoking

Next Section

Unstable angina Symptoms

Review Date: 05/23/2011
Reviewed By: Michael A. Chen, MD, PhD, Assistant Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)