Embolism is where an object, most commonly a blood clot, blocks an artery. These clots can occur in other parts of the body then break up and travel to the brain where they lodge in the brain’s smaller blood vessels.
Thrombosis is where there is a gradual closure of a blood vessel. In a stroke, it is most commonly fatty lipids called plaques building up on the walls of blood vessels and restricting blood flow. As a result, symptoms usually develop slowly but may be rapid in some cases.
Haemorrhage is severe bleeding. Two kinds can cause a stroke. An intracerebral haemorrhage is caused by a ruptured artery leaking blood directly into the brain. A subarachnoid haemorrhage occurs on the surface of the brain, and the blood fills the space around the brain and creates pressure.