Corticosteroids, often known as steroids, are an anti-inflammatory medicine prescribed for a wide range of conditions. They're a man-made version of hormones normally produced by the adrenal glands (two small glands that sit on top of the kidneys).Corticosteroids are available in different forms, including:orticosteroids, often known as steroids, are an anti-inflammatory medicine prescribed for a wide range of conditions. They're a man-made version of hormones normally produced by the adrenal glands (two small glands that sit on top of the kidneys). Corticosteroids are available in different forms, including: