No matter how many times a day we wash our hands, clean our house or wash our dishes, we’re still surrounded by bacteria and viruses which can cause illness and disease. So we rely on our immune system to fight off these potential threats constantly. In most people, the immune system operates as an effective –- even if not perfect – defensive mechanism.
But in some people the immune system may go awry, causing it to perceive parts of the body itself as a threat and attack the body’s own tissues and cells. This is what happens in type 1 diabetes, where the immune system targets cells in the pancreas that make insulin. It also happens in rheumatoid arthritis, when the immune system attacks the lining of the joints. Both of these are examples of autoimmune diseases.
Oxford is a subscribing member of The Conversation. Find out how you can write for The Conversation.