Anesthesiologists are concerned with smoking in terms of cardiovascular system. Carbon monoxide from Smoking causes the decrease of oxygen supply in blood. On the other hand, Nicotine causes release of stored fats in the blood, which stick to blood vessel walls. Moreover, it causes vascularization (new blood vessels within vessels), which provide a rich supply of oxygen and nutrients to the fats and plaques stuck to the vessel walls. This causes narrowing and clogging of the arteries.

Smoking affects lungs by causing narrowing of small airways in the lungs. Various studies reveal that smoking increases the chances of pulmonary complications after an anesthesia.

Quit smoking at least four weeks before the surgery to decrease the risk of complications significantly. Patients who could quit smoking ten weeks or more before the surgery have as lesser risk as non-smoker patients have.