The hazards of smoking for girls include lung cancer, atherosclerosis, high blood pressure, endocrine disorders and malignant tumors of the reproductive system. 1. Lung Cancer: Smoking is the most common cause of lung cancer, more than 80% of lung cancer patients have long-term smoking history, and the amount and duration of smoking are positively correlated with the incidence of lung cancer. The amount and duration of smoking are positively correlated with the incidence of lung cancer. Tobacco has been classified as a class A carcinogen, and the longer you quit smoking, the lower the risk factor of lung cancer. 2. Atherosclerosis: The incidence of atherosclerosis in smokers is about 2 to 6 times that of non-smokers, which is due to the reduced secretion of prostacyclin in smokers, resulting in platelets adhering to arterial walls more easily. Tobacco nicotine in the role of the myocardium and coronary artery leading to myocardial damage and coronary artery spasm. 3. Hypertension: Smoking inhibits the vasodilatory effect of nitric oxide through oxidative stress on the one hand, and prompts the release of norepinephrine from the sympathetic nerves on the other hand, resulting in elevated blood pressure. 4. Endocrine disorders: nicotine, polycyclic aromatic hydrocarbons and other harmful substances in cigarettes can reduce ovarian function, reduce the release of sex hormones and inhibit ovulation, thus leading to menstrual disorders and even infertility. 5. Malignant tumors of the reproductive system: Studies have found that smoking can increase the mucosal lesion effect of HPV (human papillomavirus) infection and increase the chances of HPV infection leading to cervical cancer and other malignant tumors of the reproductive system. For the sake of health, it is recommended that girls should not smoke, and should quit smoking as soon as possible if they do.