Drug abuse refers to the excessive and destructive use of drugs or substances, often leading to negative consequences for the individual using them. It can involve taking a drug in ways other than as prescribed by a doctor, such as taking higher doses, more frequently, or through different routes of administration (e.g., snorting, injecting). Drug abuse can result in physical and psychological harm to the user, including addiction, damage to vital organs, mental health issues, and social problems such as job loss, legal troubles, and relationship difficulties.