Hundreds of steroids are found in fungi, plants, and animals. All steroids are manufactured in cells from a sterol: cholesterol (animals), lanosterol (opisthokonts), or cycloartenol (plants). All three of these molecules are produced via cyclization of the triterpene squalene. [4] Many types of steroids exist. Learn about the different types, what they are used for, and safety considerations. Anabolic steroids are often used illegally to build muscle. But corticosteroids are used to treat a variety of health problems. Learn more about steroids. How do corticosteroids work? Corticosteroids help lessen swelling and irritation, called inflammation. The medicine can ease symptoms of inflammatory conditions, such as arthritis, asthma and skin rashes. Corticosteroids also lower immune system response. Prednisone is used to treat allergic disorders, skin conditions, ulcerative colitis, Crohn’s disease, arthritis, lupus, psoriasis, asthma, chronic obstructive pulmonary disease (COPD) and many more conditions. Steroids are man-made medicines similar to natural body hormones, used to treat many conditions. They reduce inflammation and the activity of the immune system. Steroids come in various forms, including oral tablets, creams, nasal sprays, and inhalers. Side-effects are more common with oral steroids or long-term use. Find out more about steroids, the different types of steroid medicine, side effects and how to stop taking them safely.