One reason for a man or a woman not to smoke is that a man is likely to end up with erectile dysfunction and the woman with premature aging with wrinkles on face

It has been shown that men who smoke more than 20 cigarettes a day have 60% higher risk of erectile dysfunction as compared to those who never smoke. Fifteen percent of past and present smokers experience erectile dysfunction. Men, who are current smokers or are former smokers, are 30% more likely to suffer from erectile dysfunction. Among men who never smoke, only 12% end up with erectile dysfunction.

Smoking increases the risk of erectile dysfunction by more than 50% in men in the 30–40 year age group. Diabetes, high blood pressure and high cholesterol are other important risk factors for erectile dysfunction.

Apart from erectile dysfunction, smoking also causes reduced volume of ejaculation, low sperm count, sperm shape etc.

In women, smoking leads to premature aging with formation of wrinkles on the face.