Heroin facts about withdrawal cover a wide range of symptoms that occur after stopping or dramatically lowering ones heroin use. Heroin withdrawal is caused by physical dependence. This means that a person relies on heroin to prevent symptoms of withdrawal. Over time, greater amounts of heroin become necessary to produce the same effect. The time it takes to become physically dependent varies with each individual.

In every year from 1995 to 2005, most Treatment Episode Data Set (TEDS) admissions for primary heroin addiction injected the drug. However, the proportion of primary heroin admissions who injected the drug declined from 69 percent in 1995 to 63 percent in 2005 (despite an 8 percent increase in the number of such admissions over this time period). Although inhalation has remained the second most frequent route of administration, the proportion of primary heroin admissions who inhaled the drug increased from 27 percent in 1995 to 33 percent in 2005.

Social issues of addiction focus on how heroin addicts relate to their environment, including interpersonal and family relationships, employment and legal problems.

By the turn of the twentieth century, the addictive properties of cocaine had become clear, and the problem of cocaine abuse began to capture public attention in the United States.