(HealthDay News) -- Lupus is an "autoimmune" disease that occurs when the body's disease-fighting system can't tell the difference between germs and the body's own, healthy tissue.

The National Women's Health Information Center says here are typical warning signs of lupus:

• Pain and stiffness in the joints that may be accompanied by swelling.
• Pain in the muscles.
• Extreme fatigue.
• Fever that can't be explained.
• A skin rash, possibly one that spreads across nose and cheeks and is shaped like a butterfly.
• Anemia or kidney problems.
• Pain in the chest when breathing in deeply.
• Sensitivity to the sun or light.
• Hair falling out.