Methimazole is a medication primarily used to treat hyperthyroidism, a condition where the thyroid gland produces too much thyroid hormone. It works by inhibiting the production of these hormones, helping to restore normal levels in the body. This can alleviate symptoms such as weight loss, rapid heartbeat, and anxiety. Patients taking methimazole may need regular blood tests to monitor their thyroid hormone levels and check for potential side effects. Common side effects can include rash, itching, or gastrointestinal issues. It is important for patients to follow their healthcare provider's instructions while on this medication.