This booklet is about acute coronary syndromes (ACS). It is based on the recommendations from a national clinical guideline on how to look after patients with ACS. It tells you about the tests and treatment that you may receive. Your family and friends may also find this booklet helpful. The booklet covers: y assessment and diagnosis; y treatment during the first 12 hours; and y treatment after 12 hours of symptom onset. We have listed a number of support organisations at the end of the booklet where you can get more information.