Lupus is an autoimmune disease where the body's immune system becomes hyperactive and attacks normal, healthy tissue. This results in symptoms such as inflammation, swelling, and damage to joints, skin, kidneys, blood, the heart, and lungs.
Under normal function, the immune system makes proteins called antibodies in order to protect and fight against antigens such as viruses and bacteria. Lupus makes the immune system unable to differentiate between antigens and healthy tissue. This leads the immune system to direct antibodies against the healthy tissue - not just antigens - causing swelling, pain, and tissue damage.
Certain environmental factors have been known to cause lupus symptoms. These include:
Extreme stress Exposure to ultraviolet light, usually from sunlight Smoking Some medications and antibiotics, especially those in the sulfa and penicillin groups Some infections, such as cytomegalovirus (CMV), parvovirus (such as fifth disease), hepatitis C infections, and the Epstein-Barr virus (in children) Chemical exposure to compounds such as trichloroethylene in well water and dust