Systemic lupus erythematosus (SLE) is the most common form of lupus — it’s the type that 7 in 10 people with lupus have. It's what most people mean when they say "lupus." 

What causes SLE?

Experts don’t know what causes SLE. Many scientists believe that lupus develops in response to a combination of factors both inside and outside the body. This includes hormones, genetics, and environment.

Read more about the possible causes of lupus.

Who is at risk for developing SLE?

Anyone can get lupus, but some people are at higher risk. This includes:

• Women ages 15 to 44
• People from certain racial or ethnic groups — including Black or African American people, Hispanic/Latino people, American Indian/Alaska Native people, and Asian Americans and Pacific Islanders
• People who have a family member with lupus or other autoimmune diseases

What are the symptoms of SLE?

Symptoms of SLE vary from person to person. They may come and go and change over time. Lupus shares symptoms with other diseases, which can make it difficult to diagnose. The most common symptoms include:

• Skin rashes
• Pain or swelling in the joints (arthritis)
• Swelling in the feet and around the eyes (typically due to how lupus affects the kidney)
• Extreme fatigue (feeling very tired all the time)
• Low fevers

Read more about lupus symptoms.

Can SLE look different for different people?

Yes. The way lupus happens and the symptoms it causes can vary a lot from person to person. Doctors and researchers may use certain terms to describe the different ways lupus can affect the body. For example:

• Lupus nephritis. This is when lupus causes the kidneys to become inflamed, which can damage them and affect how well they work. Lupus nephritis can affect up to 60 percent of people with SLE. For most people with lupus nephritis, their symptoms develop within 5 years of when their lupus symptoms first started.
• Neuropsychiatric lupus (NPSLE). This is also called “lupus with central nervous system (CNS) involvement.” This means that a person’s lupus is causing symptoms that affect their brain, like headaches, trouble thinking, memory loss, seizures, or stroke. Experts are learning more about NPSLE, but they estimate that more than 1 in 5 people with lupus have neuropsychiatric symptoms.
• Childhood-onset lupus (cSLE). Also called “pediatric lupus,” cSLE means lupus that starts in childhood. cSLE tends to be more serious than lupus that starts in adulthood. (Note that this is different from neonatal lupus, which is not true lupus and generally goes away on its own within 6 months.)
• Refractory lupus. The goal of treating lupus is to put it into remission — meaning that you have long periods without any lupus symptoms or flare ups. If you have refractory lupus, it means lupus that doesn’t go into remission even after treatment. Having refractory lupus raises your risk of having serious health problems caused by lupus.

What are possible complications of SLE?

Because lupus can affect many areas of the body, it can cause many different types of complications. Here are some of the more serious complications that can happen:

• High fevers, seizures, and behavior changes. These are caused by inflammation of the blood vessels in the brain. Note that this is different than NPSLE, even though it causes some of the same symptoms.
• Heart attack. This can be caused by hardened arteries or coronary artery disease (when fatty deposits build up in the arteries that bring blood to the heart).
• Rashes, sores, and ulcers. These are caused by skin inflammation. Most people with SLE will have skin symptoms, and about half of all people with lupus will develop a butterfly-shaped rash called malar rash. This rash usually appears across the cheeks and nose and can get worse in the sunlight.

Read more about how lupus affects different parts of the body.