Updated January 20, 2015.

Definition:
Also known as hardening of the arteries, atherosclerosis occurs when cholesterol, cellular waste, calcium and other substances are deposited along the lining of artery walls in a person's body. These deposits are called plaque, and they can build up over time, hindering blood flow.

Tobacco smoke puts a person at risk for atherosclerosis by aggravating known risk factors for this disease:

• Cholesterol
  The toxins in tobacco smoke lower a person's high density lipoprotein cholesterol (HDL or "good" cholesterol) while raising levels of low-density lipoprotein cholesterol (LDL or "bad" cholesterol).
  
  High Blood Pressure
  While cigarette smoking won't cause high blood pressure, if a smoker has hypertension, smoking can increase the risk of malignant hypertension, a dangerous form of high blood pressure. Smoking is hard on the heart.

Also, the nicotine and carbon monoxide in cigarette smoke damage the endothelium, which makes it easier for plague to adhere to artery walls..

See also:  How Smoking Causes Atherosclerosis