Substance abuse is among one of the major problems plaguing our society. It has come to the attention of several healthcare professionals that a communication gap exists between themselves and substance abusers. Most of the time the substance abusers are only familiar with the slang terms of abused substances, a terminology that medical professionals are usually unaware of. This paper is an attempt to close that communication gap, allowing health care professionals to understand the slang terminology that their patients use, thus enabling them to make appropriate treatment decisions. In addition, the article presents some key features (including active ingredient, pharmacological classification, medical use, abuse form, usage method, combinations used, effects sought, long-term possible effects, and detectability in urine) of the most commonly abused substances.