Lupus is a type of autoimmune disease. In an autoimmune disease, something goes wrong in the body’s immune system, causing it to harm healthy organs, tissues, and cells. “Auto” means “self” — so if you have an autoimmune disease, your immune system is working against your own body.

It’s possible to have more than one autoimmune disease at a time. In fact, about 1 in 4 people with an autoimmune disease go on to develop at least one other autoimmune disease. Read about common diseases that overlap with lupus.

What happens in the immune system when you have lupus?

The immune system and its role

When it’s working properly, your immune system helps to keep your body healthy. It protects your body from germs that can make you sick — like bacteria, viruses, parasites, or fungi — and from harmful substances in your environment. Collectively, these germs and harmful substances are called antigens.

To rid the body of antigens, cells from your immune system called B cells make proteins called antibodies. These antibodies find specific antigens and attach, or bind, to them so that the antigen can no longer cause harm.

Another type of cells from your immune system called T cells also find and disable antigens. As B and T cells find antigens, they trigger your immune system to make more cells to help protect you from getting sick. 

It’s important to know that the immune system is very complex. Experts are still working to understand exactly how it works — and why problems with the immune system happen.

Autoimmunity and autoantibodies in lupus

When the immune system is working to remove antigens from the body, it causes some inflammation that damages healthy tissue. Typically, this damage is very minor and doesn’t cause any health problems. But in an autoimmune disease like lupus, the immune system becomes overactive and starts harming the body. This is called autoimmunity.

With autoimmunity, the immune system creates autoantibodies: antibodies that find and bind to healthy cells instead of antigens. The overactive immune system also causes too much inflammation, which can lead to long-lasting damage to the body’s healthy tissues.

There are many different types of autoantibodies, but antinuclear antibodies (ANAs) are one of the most common types for people with lupus. In fact, 98 out of every 100 people with lupus have ANAs. These autoantibodies bind to a part of your cells called nucleic material. One way that doctors can diagnose lupus is by running a test to check for ANAs in your blood. Learn more about ANA tests.

People with lupus may also have antiphospholipid antibodies. These autoantibodies bind to proteins found in the membranes of your cells and in some cases can be related to high risk for blood clots or pregnancy complications. Read more about antiphospholipid antibodies.

Lupus flares

With lupus, people generally experience 2 phases: remissions and flares. Remissions are periods of time when your symptoms improve and you feel better. When lupus is in remission, your body produces fewer autoantibodies and you experience less inflammation.

Flares (also called active disease) are periods of time when your symptoms get worse, and you may develop new symptoms you didn’t have before. During a flare, inflammation and autoantibody activity increase. Lupus flares can look different for different people — and your symptoms depend on which system in your body your lupus is affecting.

Experts are still working to understand why lupus flares happen. But some well-known triggers, or things that can cause a lupus flare, include:

• Emotional stress — like the death of a loved one or a divorce
• Physical stress — like surgery, an injury, pregnancy, or giving birth
• Infections, colds, and illnesses caused by viruses (like the flu)
• Exhaustion
• Ultraviolet (UV) light from the sun or manmade lights

Avoiding these triggers can help you keep your lupus in remission.

Read more about lupus flares and triggers.

Impacts of autoimmunity from lupus the body

Inflammation from lupus damages healthy tissues in the body — sometimes permanently. Keep in mind that you may experience different symptoms or health issues depending on which body systems are affected during a flare. For example, if lupus causes inflammation in your kidneys (called lupus nephritis), it can keep your kidneys from working properly.

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