Lupus is an autoimmune disease. The immune system's job is to fight foreign substances in the body, such as germs and viruses. But in autoimmune diseases, the immune system attacks healthy tissues, not germs. Lupus is a disease that can affect many parts of the body. Lupus can involve the joints, the skin, the kidneys, the lungs, the heart, and/or the brain. If you have lupus, it may affect several parts of your body. Usually, one person doesn't have all the possible symptoms.
We don't know what causes lupus. There is no cure, but in most cases lupus can be managed. Lupus sometimes seems to run in families, which suggests the disease may be hereditary. Having the genes isn't the whole story, though. The environment, sunlight, stress, and certain medicines may trigger symptoms in some people. Other people who have similar genetic backgrounds may not get signs or symptoms of the disease. Researchers are trying to find out why.
The different types of lupus include: Systemic lupus erythematosus (eh-RITH-eh-muh-TOE-sus) is the most common form. The word "systemic" means that the disease can involve many parts of the body. SLE symptoms can be mild or serious. Discoid lupus erythematosus mainly affects the skin. A red, circular rash may appear, or the skin on the face, scalp, or elsewhere may change color. Discoid lupus rashes often leave scars or light-colored patches of skin after it heals. Drug-induced lupus is triggered by a certain drugs. It's like SLE, but symptoms are usually milder. Most of the time, the disease goes away when the medicine is stopped. More men develop drug-induced lupus because the drugs that cause it, hydralazine and procainamide, are used to treat heart conditions that are more common in men.
Lupus may be hard to diagnose. It's often mistaken for other diseases. For this reason, lupus has been called the "great imitator." The signs of lupus differ from person to person. Some people have just a few signs; others have more.