Corticosteroid medicines-also called steroid medicines-are similar to natural hormones produced in the body that help control many necessary functions, including blood sugar and salt (electrolyte) levels, the body's water balance, and immune system function. These medicines may help provide relief for diseases that cause inflammation, such as lupus and rheumatoid arthritis.

Common prescription steroid medicines include dexamethasone, hydrocortisone, and prednisone.

Steroid medicines have many side effects. The side effects a person has may depend on the steroid dose and how long the medicine is taken. Side effects like problems sleeping, mood changes, weight gain, and increases in blood sugar may occur shortly after starting a steroid medicine. Other side effects like changes in the colour and thickness of skin, formation of cataracts, increases in blood pressure, and a reduced ability to fight infections may develop over time or at higher doses.