Health effects of tobacco (English: Health effects of tobacco) refers to the harmful effects of regular use of tobacco on human health. Initial research was primarily on the subject of tobacco smoking.   In 1950, Richard Doll, a scientist, published a study in the British Medical Journal in which he mentioned a link between smoking and lung cancer.  Another study called the British Doctors Study was published in the year which is the result of a twenty year study of forty thousand doctors. There the link between smoking and the lungs is confirmed, on the basis of which the government announces that smoking increases the rate of lung cancer.
The risk of premature death can be reduced by eliminating the use of tobacco products.  About half of all people who use tobacco die from its harmful effects.  The World Health Organization estimates that approximately 6 million people worldwide die each year from the harmful effects of tobacco (about 10% of all deaths), with about 7 million admitting to secondhand smoke. Tobacco has killed nearly 100 million people in the twentieth century.  The United States Centers for Disease Control and Prevention (CDC) has also cited it as one of the leading causes of premature death worldwide. 
Tobacco mainly affects the heart, liver and lungs. Smoking increases the risk of heart attack, stroke, chronic obstructive pulmonary disease (COPD) (including emphysema and chronic bronchitis), and cancer (especially lung cancer, cancer of the pancreas, larynx and oral cancer). Tobacco can cause high blood pressure and peripheral vascular disease. The effect depends on how much a person smokes daily and for how many years. Cigarettes from a young age and with a high concentration of tobacco can increase the risk. Tobacco smoke and secondhand smoke from the environment can also have harmful effects on people of all ages.  Tobacco has a wide range of harmful effects on pregnant women. The rate of miscarriage is higher in women who smoke. It also causes a lot of damage to the fetus, such as premature birth, low birth weight (LBW) and sudden infant death syndrome (SIDS) by 1.4-3%.  Smokers are 85% more likely to develop erectile dysfunction during sexual intercourse than non-smokers.  
Some countries are taking steps to reduce tobacco use and sales. In addition, the rule of writing warning messages on the packaging of tobacco products has been made mandatory. In addition, efforts are being made to increase the price of tobacco by imposing additional taxes on it, which is expected to benefit developing countries.  Cigarettes contain more than 50 chemicals that can cause cancer in the human body.  Tobacco contains another substance called nicotine. Which is responsible for the creation of addiction. Smoking nicotine creates physical and mental dependence. Cigarettes sold in underdeveloped countries contain high levels of tobacco products, which can increase the risk of smoking or disease.