Why do people get stroke?

Strokes can be caused by a number of things. The most common type of stroke is ischemic ("is-KEY-mik") stroke. Ischemic strokes are often the result of clot or thrombus formation affecting the circulation within the brain - sometimes due to the rupture of an athersclerotic plaque within the lining of blood vessels or sometimes even due to arrhythmias of the heart. This results in a lack of oxygenated blood reaching brain cells (which have a very high demand for oxygen and die quickly without it). People with cardiovascular disease, dyslipidemias (e.g. high cholesterol), who smoke, or have a family history of cardiovascular disease are at a higher risk of stroke. Ischemic strokes can also be the result of a sudden rapid drop in blood pressure which prevents adequate supply of blood to the brain.
A less common type of stroke is hemorrhagic stroke (bleeding stroke). In this situation, a blood vessel within the brain ruptures and leaks blood into the surround brain tissue. This ruputure prevents blood from reaching areas of the brain further along the vessel and causes irritation to brain cells (due to the pooled blood). Some people are at higher risk of this type of stroke due to their genes, uncontrolled hypertension, or even as the result of a head trauma.
Hopefully this helps answer your question. The Heart and Stroke foundation also has useful information at www.heartandstroke.com .

when you eat unhealthy foods, your arteries get clogged, and then you can develop a blood clot. if this blood clot travels to your brain and blocks off an artery leading to your brain, that part of your brain will not recieve the blood and oxygen it needs, and that is how you have a stroke.

people get hypercoagulated- which means the their blood is clotting when it is not suppose to- the clot breaks free in the brain causing a stroke or a TIA- a small recoverable stroke.

A disturbance of the arteries to the brain

there are two types of stroke-haemorrhagic and ischaemic
haemorrhagic type is mostly caused by uncontrolled hypertension(high BP),which causes a small blood vessel in the brain to break causing stroke
ischaemic means there is compromise in the blood supply.this can be due to blockage of a small cerebral artery by a clot(can arise from a diseased heart or elsewhere) or blockage by a fragment of an atherosclerotic plaque(the substance that gets deposited in arterial walls due to high cholesterol etc )

Brain attack.
Clogged artery in the brain.