Substance use disorder is a complex condition marked by the compulsive use of drugs or alcohol despite adverse consequences. It can disrupt daily functioning by impairing one’s ability to work, maintain relationships, and engage in everyday activities. The causes of substance use disorder are multifaceted, involving genetic, biological, environmental, and psychological factors. Symptoms vary but often include intense cravings, loss of control over substance use, withdrawal symptoms, and significant changes in behavior. Substance use disorder can be a debilitating condition, but with effective treatment, many individuals find relief and improvement in their lives.