According to National Institute on Drug Abuse, drug addiction is a brain disease and it also affects other part of body. Cardiovascular disease, stroke, cancer, HIV/AIDS, hepatitis, and lung disease can be affected by drug abuse, the institute said. Tseten Yeshi, Senior Research Scientist at Transposagen Biopharmaceuticals Inc, explains how addiction occurs chemically and its damaging effect on one’s health. Sources: National Institue on Drug Abuse; Interview with Trilan Palmo, Director of Community Health Program, and Tseten Yeshi, PhD. Senior Research Scientist at Transposagen Biopharmaceuticals Inc.