Substance withdrawal refers to the physical and mental symptoms that occur when a person reduces or stops using a substance they have become dependent on, 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 may include anxiety, irritability, nausea, sweating, and tremors. In some cases, withdrawal can be severe and may require medical supervision to ensure safety and manage complications. Treatment options often include medication, therapy, and support groups to help individuals recover and maintain sobriety.