Information for the public
Unstable angina and NSTEMI
Unstable anginaand NSTEMI are both heart conditions that need treatment and are often a warning of more serious problems in the future. They may cause chest pain or discomfort. The pain is caused by a blockage or narrowing of one of the main blood vessels to the heart (coronary arteries). This usually happens when a person has coronary heart disease, which is caused by a build up of fatty materials in the walls of the artery.
In people with angina, tightness or pain in the chest is typically brought on by exercise, emotional distress, cold weather, or activity after eating a large meal. Angina is called 'unstable' when it has developed suddenly, has suddenly got worse or occurs at rest.
NSTEMI is a type of heart attack that happens when one of the coronary arteries suddenly becomes partly blocked by a blood clot. The name NSTEMI comes from the pattern seen on a test called an electrocardiogram, or ECG, which measures the rhythm and electrical activity of the heart. Other types of heart attack, such as ST-segment-elevation myocardial infarction (STEMI), are not covered by this guideline.
Unstable angina and NSTEMI are similar in many ways and the early stages of their treatment are also similar.