An immune system disorder. Your body protects itself with the immune system. The immune system makes proteins called antibodies. These protect against bacteria, viruses, and cancer cells. In some people, the immune system makes antibodies that attack the body’s own cells. This leads to inflammation and tissue damage in the body.
In the United States, an estimated 1.5 million people live with lupus. About 16,000 new cases are diagnosed annually. Experts believe lupus may be caused by a mix of genes and other factors, such as exposure to the Epstein-Barr virus (EBV), which causes mononucleosis. Other environmental factors such as exposure to sunlight and physical factors such as stress or hormones (specifically the female hormone estrogen) can trigger lupus.
Lupus is not a contagious disease, meaning you cannot catch or spread it.
Drug-induced lupus. In some instances, drug-induced lupus is caused by a reaction to prescription medications. An estimated 10 percent of people with lupus have symptoms due to this kind of reaction. Around 80 drugs may cause the condition, including some blood pressure medications, anti-seizure drugs, and antibiotics.