Methylprednisolone 4 mg is a corticosteroid (glucocorticoid) medicine used to reduce inflammation and suppress an overactive immune response. It may be prescribed for conditions such as severe allergies, asthma and other respiratory inflammatory conditions, arthritis, skin disorders, and certain autoimmune or inflammatory diseases. It should be taken strictly according to the doctor's prescribed dose and duration, as prolonged or inappropriate use can cause significant side effects.