The slogan that smoking is harmful to health can be seen everywhere. What harm does smoking do to the human body? How are these harms caused?

1. Cigarettes carry germs. The latest research has found that cigarettes carry many germs, which are inhaled into the body during the smoking process. Their pathogenic mechanism is not yet clear, but it is an irrefutable fact that cigarettes carry pathogens.

2. Smoking affects sexual function. Smoking affects blood circulation and reduces blood flow to the genitals, which can lead to difficulty in sexual arousal (both for men and women). A large-scale survey in China in 2007 also found that 20% of male erectile dysfunction was related to smoking.

3. Smokers have poor sleep quality. A study by Johns Hopkins University in the United States found that smokers are four times more likely to remain sleepy after waking up from a night's sleep than non-smokers. Researchers analyzed that the reason is that smokers' bodies cannot obtain nicotine during sleep at night. Although they seem to be sleeping soundly, their sleep is actually disturbed many times and the quality of their sleep is reduced.

4. Smokers’ bones are very fragile. Studies have found that for every 10 years of smoking for female smokers, their bone mineral density will decrease by 2.3% to 3.3%. This decrease in bone density will lead to a significant increase in the incidence of fractures and osteoporosis. The risk is greater in menopausal women.

5. Smoking increases the risk of deafness and blindness. The latest research found that compared with non-smokers, smokers have a nearly 70% increased risk of hearing loss. A large-scale survey of more than 20,000 men found that smoking also increases a man's chance of vision loss. Smoking also increases the risk of macular degeneration, the number one killer of vision.

6. Smoking causes psoriasis. Multiple studies have shown that daily smoking is associated with an increased risk of developing psoriasis. Smoking more than 20 cigarettes a day increases the risk of psoriasis.

7. Most smokers have cold hands and feet. Smoking hinders the smooth operation of blood circulation in the human body and causes insufficient blood supply to the hands and feet. Therefore, smokers are prone to cold hands and feet, and their fingers and toes are also more susceptible to frostbite.

8. Cigarettes + oral contraceptives = heart disease. The latest British study found that women who smoke and take birth control pills will increase their risk of cardiovascular and cerebrovascular diseases such as heart disease and stroke by 10 times. The reason is that smoking increases blood viscosity and is more likely to cause blood clots; birth control pills can also thicken the blood. The dual effects of "smoking + birth control pills" double the incidence rate.

9. Smoking reduces the efficacy of medicine. Smoking affects how well liver enzymes process medications, so smokers sometimes need to take higher doses to get the same effect. After quitting smoking, the dosage of certain drugs will decrease.