Crack cocaine, commonly known simply as crack, and also known as rock, is a free base form of cocaine that can be smoked. Crack offers a short, intense high to smokers. The Manual of Adolescent Substance Abuse Treatment calls it the most addictive form of cocaine. A crack addict is known as a "crackhead" Depending on the severity of crack cocaine overdose , an individual may experience one to all of the following symptoms: Agitation: When someone consumes a significant amount of crack cocaine, it is common for them to experience a state of agitation. Holding a conversation with someone in this state can be difficult. Agitation symptoms, such as nervousness and anxiety, may become magnified if they have overdosed. Black phlegm: People commonly abuse crack cocaine by smoking it. When someone chronically smokes crack, it can weaken their immune system and lessen their body’s ability to resist lung infections. Smoking crack can result in bleeding within the lungs which causes s