This introduction presents an overview on women's health. It also presents societal differences, inherent physical and medical differences between men and women. Much of the research on women's health concerns has emphasized women's genitourinary organs and diseases and childbearing diseases. Men and women often live different lives within society and the way they live affects their health. In caring for the woman with addiction, dealing with her individual circumstances is very important. Women are less likely to use smoking cessation programs, especially work-related programs, and are less likely to quit. Women are usually less likely to become infected (except with AIDS) and more likely to develop autoimmune diseases. Women are more likely to be caregivers, elderly, poor, alone and uninsured, making their health care needs and treatment different than those of men. Women's immunology, drug use and metabolism may differ and may affect the treatment of diseases.