Reproduction and fertility
Smoking can cause male impotence, as it damages the blood vessels that supply blood to the penis. It can also damage sperm, reduce sperm count and cause testicular cancer. Up to 120,000 men from the UK in their 20s and 30s are impotent as a direct result of smoking, and men who smoke have a lower sperm count than those who are non-smokers.
For women, smoking can reduce fertility. One study found that smokers were over three times more likely than non-smokers to have taken more than one year to conceive. The study estimated that the fertility of smoking women was 72% that of non-smokers.
Smoking also increases your risk of cervical cancer. People who smoke are less able to get rid of the HPV infection from the body, which can develop into cancer.
Smoking while you are pregnant can lead to miscarriage, premature birth, stillbirth and illness, and it increases the risk of cot death by at least 25%.