Heroin is an illegal and highly addictive opioid drug derived from morphine, which is found in poppy plants. It has many street names and is often mixed with other substances like sugar, starch, or poisons like strychnine. Short-term effects include feelings of euphoria but also vomiting and constipation. Long-term heroin use can damage major organs and lead to collapsed veins, infections, liver and kidney disease, and impotence. Withdrawal from heroin causes painful cravings, muscle aches, and vomiting. While treatment programs exist, heroin addiction frequently leads to relapse due to cravings. Possession or sale of heroin carries legal penalties including jail time and fines.