With regular heroin use, tolerance develops. As a result, the user must use more heroin to get the same effect. As the person uses higher doses over time, addiction develops. Withdrawal can occur as early as a few hours after the last use, and produces drug craving, restlessness, muscle and bone pain, insomnia, diarrhea and vomiting, cold flashes with goose bumps, kicking movements, and other symptoms. Major withdrawal symptoms peak between 48 to 72 hours after the last dose and subside after about a week.
Sudden withdrawal can be fatal.