A stroke occurs when the brain does not receive enough oxygen.
This can occur when there is some form of blockage in the arteries that supply blood to the brain. These blockages are most commonly due to atherosclerosis. High cholesterol is a major causative factor of atherosclerosis. It does so by laying down fatty deposits in the arterial wall (Heart Foundation, 2014). Atherosclerotic fatty deposits that have bonded to the arterial wall may break off, blocking the artery and in turn blocking blood flow. The increased stress to the blood vessel can also weaken the arterial wall, leading to a haemorrhage (National Stroke Association, 2014).
In addition to atherosclerosis, which thins the arteries, high blood pressure is also a leading cause of stroke. It can cause a stroke as it puts unnecessary stress on the blood vessel walls, causing them to thicken and deteriorate (American Heart Association, 2013).