Lupus is a condition in which the body's immune system attacks its own tissues and organs. This is called an autoimmune condition. Lupus causes swelling and irritation, called inflammation, that may affect joints, skin, kidneys, blood cells, brain, heart and lungs.
Lupus can be hard to diagnose because its symptoms often are like those of other illnesses. A common sign of lupus is a facial rash that looks like butterfly wings across both cheeks. The rash gets worse when in the sun. Many but not all people with lupus get this rash.
Some people are born more likely to get lupus. Infections, certain medicines or even sunlight can trigger the condition. There's no cure for lupus, but treatments can help manage symptoms.
How lupus shows up isn't the same for everyone who has it. Symptoms may start suddenly or slowly. They may be mild or serious, brief or lasting.
People with lupus may have flares. During flares, symptoms get worse for a while, then get better or go away for a time.
The symptoms of lupus depend on which body systems the condition affects. The most common symptoms include:

A typical sign of lupus is a butterfly-shaped rash over the cheeks and nose. It often happens after being in sunlight. The rash may look red on white skin and be harder to see on Black or brown skin.
See your healthcare professional if you get a rash or other symptoms that worry you.
Experts don't know the cause of lupus. It's likely that genes and factors in the environment together cause lupus.
Certain factors trigger lupus in people who have the genetic changes that make them more likely to get the condition. Factors include:
Factors that may raise your risk of lupus include:
The swelling and irritation, called inflammation, that lupus causes can affect all or some of the following:
Having lupus also increases your risk of:
Pregnancy complications. Pregnant people with lupus have a higher risk of losing the pregnancy, called miscarriage. Lupus raises the risk of high blood pressure during pregnancy and of giving birth too early. To lower the risk of these complications, healthcare professionals often suggest waiting to get pregnant until the lupus is well managed.
Another choice is using medical techniques to protect being able to have children. Done before treatment, this is called fertility preservation.