A "side effect" refers to an unintended consequence of a medication or treatment. While the primary goal of a drug is to treat a specific condition, side effects can occur, affecting other parts of the body. These effects can be mild, such as a headache, or more severe, like allergic reactions. Side effects can vary from person to person, influenced by factors like age, genetics, and overall health. It's important for patients to discuss potential side effects with their healthcare provider to make informed decisions about their treatment options, ensuring that the benefits outweigh the risks associated with the medication.