What is lupus?
Lupus is a chronic (long-term) disease that can cause inflammation and pain in any part of your body. It’s an autoimmune disease, which means that your immune system — the body system that usually fights infections — attacks healthy tissue instead.
What is inflammation?
Inflammation usually happens when your immune system is fighting an infection or an injury. When lupus makes your immune system attack healthy tissue, it can cause inflammation in lots of different body parts. Symptoms can include swelling and pain.
Lupus most commonly affects your:
- Skin
- Joints
- Internal organs, like your kidneys and heart
Because lupus affects many parts of the body, it can cause a lot of different symptoms.
Learn more about lupus signs and symptoms
What are the types of lupus?
When people talk about lupus, they’re usually talking about systemic lupus. But there are other types — including cutaneous lupus, drug-induced lupus, and neonatal lupus.
Learn more about the different types of lupus
Who is at risk for developing lupus?
Anyone can develop lupus. But certain people are at higher risk for lupus, including:
- Women ages 15 to 44
- Certain racial or ethnic groups — including people who are African American, Asian American, Hispanic/Latino, Native American, or Pacific Islander
- People who have a family member with lupus or another autoimmune disease
9 out of 10 people with lupus are women.
Read more facts and statistics about lupus
What causes lupus?
No one knows what causes lupus — but lupus and other autoimmune diseases do run in families. Experts also think it may develop in response to certain hormones (like estrogen) or environmental triggers. An environmental trigger is something outside the body that can bring on symptoms of lupus — or make them worse.
Lupus is not contagious—you can’t “catch” lupus or give it to someone else.
Learn more about possible causes and triggers of lupus
Want to print information about lupus? Download our Understanding Lupus fact sheet:
- English: Understanding Lupus [PDF - 1.3 MB]
- Spanish: Entendiendo el lupus [PDF - 2 MB]
- Chinese (Simplified): 了解狼疮 [PDF - 1.4 MB]