Tips on understanding strokes

Strokes are more complicated than heart attacks because they can happen different ways. Here is some information on different types of strokes and triggers. 

• The majority are called ischemic strokes and are caused by a clot blocking a blood vessel that has been narrowed by atherosclerosis. The clot may have formed following a rupture of plaque, which happens in the most common form of heart attack, or it may have traveled from the heart, one of the arteries in the neck or elsewhere in the body.
• Clots that move through the bloodstream this way are known as emboli, and when they lodge in the brain the event is called a cerebral embolism.
• However, around one in five strokes is due to bleeding in the brain following the tearing of an artery wall. This is known as a hemorrhagic stroke and is particularly likely to occur in an individual with high blood pressure. The effects of a hemorrhagic stroke are often more severe than those of ischemic strokes, and the treatments for the two types of strokes are very different.

• Both heart attacks and strokes are generally the result of atherosclerosis that has built up over decades, but the culmination of this process in a sudden attack is often preceded by an event known as a trigger.Triggers have one thing in common: They prompt the nervous system to flood the body with stress hormones, putting strain on the heart and blood vessels.
• A trigger factor can result in a sudden surge in blood pressure or make the heart beat faster — occasionally beyond the point at which it is able to cope with the extra workload.
• Some triggers narrow blood vessels, prompt clots to form or increase damage to the lining of arterial walls. Others may lead to a tear in a blood vessel or an erratic heart rhythm that may cause the heart to stop altogether.