In around 90 percent of strokes, the blood supply to the brain has become blocked. Brain cells are starved of their essential food and oxygen and quickly cease functioning. This is why it is very important to act quickly if you think someone you love is having a stroke. The faster the person receives medical attention, the more of the brain you can save.

The symptoms of stroke are sudden weakness or numbness in one side of the body, confusion, sudden vision loss and speech difficulty. There may also be dizziness and in severe cases the person may lose consciousness.

How much and in what way the person is affected by their stroke depends on which part - or parts - of the brain have suffered damage. For instance, if cells were starved in the motor cortex region of the brain the person could lose some of their mobility. If the stroke was not severe, intensive nursing and therapy can often help recover some of the lost ability. The brain effectively is rewiring itself and can re-learn skills.

In more tragic cases the stroke is severe and causes permanent disabilities. For some individuals it can be fatal, for example if it occurred in the part of the brain which controls a vital function such as breathing. After cancer and heart disease it is the biggest cause of death in the developed world.

There are lifestyle changes you can make to lessen your chances of suffering a stroke. Like most serious illnesses, the most beneficial things you can do to prevent it are quitting smoking, drinking in moderation, exercising and eating a balanced diet with plenty of fruit and vegetables.

As well as lifestyle changes, there are medications which may be prescribed to high risk individuals to lessen their stroke risk. For instance, aspirin might be recommended by a doctor to thin the blood or lower blood pressure. This can prevent blood vessels from bursting and causing a clot which may block the flow of blood to the brain. There are also a growing number of surgical procedures that may work well as a stroke preventative.

Knowing about strokes is very important. Make sure you regularly remind yourself of the symptoms and act fast if necessary. Taking a moment to educate yourself about strokes may one day save your life, or the life of someone you love.