Numerous studies have shown that smoking adversely affects the endocrine glands. Particularly gonads are affected by tobacco. Toxic substances from the cigarette smoke are poisoning the sexual glands, which is connected with the occurrence of impotence among men. Inspecting the women who worked at tobacco processing factories, scientists have identified the harmful effects of hazardous substances in their body. Women had menstrual disorders, toxemia of pregnancy and miscarriages were more common. Smoking is also harmful to other endocrine glands (thyroid, adrenal glands).