Lupus -- also known as systemiclupus erythematosus -- is a disease of the immune system. Normally, the immune system protects the body from infection. In lupus, however, the immune system inappropriately attacks tissues in various parts of the body. This abnormal activity leads to tissue damage and illness.

Who Gets Lupus?

According to the Lupus Foundation of America, approximately 1.5 million people in the U.S. have lupus. People of African, Asian, and Native American descent are more likely to develop lupus than are Caucasians. Although it can occur in both men and women, 90% of people diagnosed with the disease are women. Women of childbearing age (14 to 45 years old) are most often affected and as many as 1 in 250 people may develop lupus.

What Are the Symptoms of Lupus?

The symptoms of lupus differ from one person to another. Some people have just a few symptoms, while others have many. In addition, there are many different symptoms of lupus because the disease can affect any part of the body. Some of the more common symptoms include:

  • Achy joints (arthralgia)
  • Unexplained fever (more than 100 F)
  • Swollen joints (arthritis)
  • Prolonged or extreme fatigue
  • Skin rash
  • Ankle swelling and fluid accumulation
  • Pain in the chest when breathing deeply (pleurisy)
  • A butterfly-shaped rash across the cheeks and nose
  • Hair loss
  • Sensitivity to the sun and/or other light
  • Seizures
  • Mouth or nose sores
  • Pale or purple fingers or toes from cold or stress (Raynaud's phenomenon)

via WebMD