Substance withdrawal refers to the physical and psychological symptoms that occur when a person reduces or stops using a substance, such as alcohol, opioids, or nicotine. These symptoms can vary in intensity and duration, depending on the substance and the individual's level of dependence. Common withdrawal symptoms include anxiety, nausea, sweating, and tremors. The process of withdrawal can be challenging and may require medical supervision, especially for substances like alcohol and benzodiazepines, where severe symptoms can arise. Treatment options often include medication, therapy, and support groups to help individuals manage their symptoms and maintain recovery.