Stroke is caused when certain parts of the brain stops receiving oxygen due to a rupture or a clot buildup of a blood vessel that supplies that part of the brain. This buildup is a condition called atherosclerosis.
Some causes of atherosclerosis are listed below:
Air Pollution
This might be caused when particles in the lungs, brought in by the breathing in of contaminated air, inflame lung tissues.
These swollen lung cells cause the blood cells to swell as well. As the blood cells are swollen and do not perform their duty of transferring oxygen and nutrients very well, deposits and reserves of these nutrients, especially fats, build up in the blood vessels (arteries), causing the blood vessel to be blocked or puncturing the walls of the vessel, causing it to rupture.
If atherosclerosis happens in an artery supplying the brain, it may cause that part of the brain to be damaged. This is called a stroke.
Overweight
People who are overweight tend to have an eating habit which causes them to eat a lot, unnecessarily and even when they are not hungry.
They tend to take in way more calories than their body is burning off.
All this translates to extra calories, cholesterol and fats which the body tends to store. It is this stored fat that adds weight to people and makes them look big.
If there is too much fats or calories entering from the digestive system into the blood for the blood to transport all at once, cholesterol may form deposits along the way of the vessel. Over time if the person continues eating and more calories are taken in, this cholesterol deposit in the blood vessel may grow to block the vessel.
From this, atherosclerosis forms and may lead to stroke if it happens in a major artery supplying the brain.
If the reserves of fat in the body get too much, they may constrict blood vessels. This pressure on blood vessels can cut supply of oxygen and nutrients to the brain if the constriction of blood vessels is excessive.
Little Exercise
If a person takes in more calories than he burns, the excess is stored as fat in the body. If the person is not physically active, less calories will be burnt off and the reserves of fat in the body will increase, increasing the constriction of blood vessels and/or increasing deposits of cholesterol in the body.
Exercise is a way for the body to burn off extra calories.