Taken exactly as prescribed, pain relievers can manage pain effectively. But chronic use or abuse of opioids can result in physical dependence and addiction. Dependence means that the body adapts to the presence of the drug, and withdrawal symptoms occur if use is reduced or stopped.
Symptoms of withdrawal include restlessness, muscle and bone pain, insomnia, diarrhea, vomiting, and cold flashes with goose bumps. Tolerance to the drugs' effects also occurs with long-term use, so users must take higher doses to achieve the same or similar effects as experienced initially. Addiction is a chronic, relapsing disorder characterized by compulsive drug seeking and use.