Physicians obtain information by verbally communicating with patients. But communication is frequently impaired for varied reasons. Often, physicians and patients speak different languages, even when both use English as their vernacular. Intravenous drug users have their own way of referring to their lifestyle and habits. Without understanding the terms they use, the physician will have difficulty appreciating the course of events leading up to a disease. Terms unique to the drug culture, or terms that have a different meaning to drug users than they do to the general public are defined herein. This special lexicon is the culmination of the author's 5-year file-card collection of terms.