Steroids work by decreasing inflammation and reducing the activity of the immune system. Inflammation is a process in which the body’s white blood cells and chemicals can protect against infection and foreign substances such as bacteria and viruses. In certain diseases, however, the body’s defense system (immune system) doesn’t function properly. This might cause inflammation to work against the body’s tissues and cause damage. Signs of inflammation include:
Steroids reduce the production of chemicals that cause inflammation. This helps keep tissue damage as low as possible. Steroids also reduce the activity of the immune system by affecting the way white blood cells work.