Dexamethasone is a type of medication known as a corticosteroid. It is used to reduce inflammation and suppress the immune system in various conditions, such as allergies, asthma, and autoimmune diseases. Dexamethasone can also be prescribed to help manage symptoms in certain cancers and to prevent nausea in patients undergoing chemotherapy. This medication is available in several forms, including tablets, injections, and topical creams. While effective, dexamethasone can have side effects, such as weight gain, mood changes, and increased risk of infections, especially with long-term use. Always consult a healthcare professional before starting or stopping this medication.