Heart/Increased Blood Pressure

Nicotine causes the blood vessels to constrict. As the blood vessels narrow, blood pressure rises. Undetected and uncontrolled hypertension or high blood pressure leads to heart disease. The estimated half-life of nicotine is approximately two hours. This means that nicotine remains in the bloodstream for that length of time. But since a smoker receives multiple dosing of nicotine, this drug stays in the circulatory system for much longer. The American Heart Association warns that significant levels of nicotine potentially remain in the smoker's blood for six to eight hours after the last cigarette. Hypertension is a risk factor for suffering a heart attack, stroke or premature death. Kidney and heart failure result from uncontrolled hypertension.

Nicotine causes the release of adrenalin and noradrenalin, which are hormones, produced by the adrenal glands. Once nicotine is absorbed by the alveoli in the lungs or the mucous membranes of the nose, it stimulates the release of adrenalin and noradrenalin, which are collectively referred to as catecholamines. The rapid releases of catecholamines caused by nicotine increases heart rate. A heart rate of greater than 100 beats per minute is considered a fast heart rate, or tachycardia.