. Within one minute after smoking begins, the smoker's heart rate and blood pressure begin to increase. Less obvious, but even more important, are the long-term effects of smoking on the arteries. Smoking causes the arteries to tighten up; this increases the damage to the arterial walls. Smoking also causes abnormalities in the blood clotting process, and it has harmful effects on levels of cholesterol and related substances in the bloodstream. All of these factors together worsen atherosclerosis and increase the smoker's chances of a variety of diseases including heart attacks.
Atherosclerosis is a gradual clogging and narrowing of the arteries caused by damage to the inside layer of the walls of the arteries. It develops over many years, and it can happen in arteries anywhere in the body.
Atherosclerosis is responsible for many medical problems. When it happens in the coronary arteries (the arteries that supply blood to the heart), it causes a type of heart disease called coronary heart disease which causes heart attacks, when it happens in the arms or legs it causes peripheral vascular disease, when it happens in the eye it is causes optic neuropathy, and when it happens in the brain is causes a common type of stroke.