Types of Strokes
Every stroke interrupts blood flow to the brain — but not all strokes happen the same way, or need the same treatment.
Although all strokes interrupt blood flow to a part of the brain, there are different types of strokes that affect the brain differently — and that are treated completely differently. Knowing which type someone has is critical to giving them the right treatment quickly.
A small blood clot can form in a blood vessel and block an artery in the brain. In some cases, the clot may develop elsewhere in the body and travel through the bloodstream to the brain, where it becomes lodged and blocks the vessel — preventing blood flow to parts of the brain. The medical term for this type of blood clot is an embolus.
Ischaemic strokes are the most common type of stroke, and are usually caused by the same gradual build-up of fatty plaque in the arteries (atherosclerosis) that leads to heart attacks.
When a weakened blood vessel in the brain bursts, it bleeds into the surrounding brain tissue and damages it. The two types of weakened blood vessels that may lead to a haemorrhagic stroke are called aneurysms and arteriovenous malformations.
Most haemorrhagic strokes are caused by uncontrolled blood pressure, though there are other reasons blood vessels in the brain can become weakened too. About 3 in 10 strokes are caused by bleeding — the majority are caused by clots.
A TIA occurs when the blood supply to a part of the brain is temporarily interrupted. The cause of a TIA is similar to that of a stroke, but the symptoms are usually temporary and typically resolve completely within 24 hours.
If you experience a TIA, you will have the same symptoms as a stroke — however, you will recover quickly, and a TIA usually does not cause permanent damage to the brain. Even so, a TIA is a warning sign that a full stroke may follow, and needs the same emergency response as a stroke.
Is one side of the face drooping or numb?
Is one arm weak, numb, or drifting downward?
Is speech slurred or hard to understand?
If any of these signs are present, call an ambulance immediately.
