Steroids, also known as corticosteroids, are anti-inflammatory medicines used to treat a range of conditions. They are different from anabolic steroids, which are often used illegally by some people to increase their muscle mass. Steroids are designed to act like hormones that are made naturally in the human body to reduce inflammation. They are useful in treating conditions that cause irritation and swelling, such as rheumatoid arthritis, asthma, and skin rashes. Steroids wont cure these conditions, but they are very good at reducing inflammation and will ease symptoms such as swelling, pain, and stiffness. Steroids come in many different forms, including tablets, liquids, inhalers, nasal sprays, injections, creams, lotions, and gels. Most steroids are only available on prescription, but a few (such as some creams or nasal sprays) can be bought from pharmacies and shops. Steroids do not tend to cause significant side effects if theyre taken for a short time or at a low dose. But sometimes they can cause unpleasant side effects, such as an increased appetite, mood changes, and difficulty.