Within 20 minutes of your last cigarette your blood pressure and pulse rate drop to normal, and the temperature of your hands and feet increases to normal.

After eight hours, the carbon monoxide level in your blood drops to normal and the oxygen level in your blood increases to normal.

After 12 hours, your lungs start working better.

After 48 hours, your nerve endings adjust to the absence of nicotine, and your ability to smell and taste things is enhanced.

After 72 hours, your bronchial tubes relax and your lung capacity increases, making it easier for you to breathe.

After two to three months, coughing, sinus congestion, fatigue and shortness of breath all decrease. Your body's overall energy level increases, and your chance of infection is reduced.