In your blood there are 'sticky' cells called platelets. When you cut yourself, the platelets stick to each other (clot) to seal the wound. Sometimes platelets stick to each other inside an artery - this is called a thrombus. If a thrombus forms in a blood vessel around your heart, this reduces the flow of blood to your heart. The term acute coronary syndrome (ACS) covers a range of disorders that are caused by this underlying problem. It may mean that you have had a heart attack, or that you have angina pain that is not well controlled. Antiplatelet medicines reduce the stickiness of platelets, and this helps prevent the platelets from sticking to the inside of an artery and forming a thrombus. This reduces the chances of you having a heart attack or stroke.
This is a companion discussion topic for the original article at https://patient.info/medicine/ticagrelor-tablets-brilique