Scientists aren’t sure what exactly causes lupus. But most believe it’s a combination of genes, hormones, and environment.

Genes

Genes — which your parents pass down to you — help define your body’s features and traits. And scientists have identified more than 50 genes that are more common in people with lupus.
In most cases, having these genes isn’t enough to cause lupus. But they do raise your risk of getting lupus, which is why having family members with lupus — or another autoimmune disease — makes it more likely that you’ll have lupus too.

Learn more about lupus and genetics.

Hormones

Hormones are the body’s messengers — they help keep everything balanced by sending signals between parts of the body. Because hormones play a critical role in how the body functions, researchers have looked at the relationship between various hormones and lupus. 

Since lupus is most likely to affect women ages 15 to 44, one hormone that researchers have looked at is estrogen. Women tend to have higher levels of estrogen than men, and women are also more likely to have more lupus symptoms before periods and during pregnancy when estrogen levels are high. 

However, scientists haven’t found estrogen to be a direct cause of lupus, and no causal effect has been proven between estrogen, or any other hormone, and lupus. Researchers are now focusing on differences between men and women, beyond hormone levels, which may account for why women are more prone to lupus and other autoimmune diseases.

Environment

People who are likely to get lupus (because of their genes and hormones) may develop the condition when they come in contact with something in their environment. Scientists aren’t exactly sure what in the environment causes this, but they believe it’s most likely things like:

• Ultraviolet light (UVA and UVB) from the sun
• Infections — most likely an infection with the Epstein-Barr virus
• Silica dust — which many farm and industrial workers are exposed to at their job

Other environmental causes could be:

• Medicines — like sulfa drugs, tetracycline drugs, and antibiotics
• Emotional stress — like a divorce or death of a family member
• Anything that can damage or tire your body — like injuries, surgery, or giving birth

Social determinants of health (SDOH) are the conditions in the places where you’re born, grow, work, live, and age — and they can impact your mental and physical health and your ability to get care for conditions like lupus. Some examples are safe housing, access to transportation and nutritious food, and experiences with racism and discrimination. SDOH can make managing lupus easier or harder.

In the United States, because of the effects of systemic racism, SDOH tend to negatively affect health for some groups, like people who are:

• Black/African American
• Hispanic/Latino
• Native American/Alaska Native
• Asian American/Pacific Islander

Watch out for triggers

The environmental causes of lupus are also common triggers for people with lupus. Triggers can make lupus symptoms worse — when this happens, it’s called a flare.

People with lupus don’t all have the same triggers. If you have lupus, make a note of when a flare happens and what triggers may have caused it to help you notice any patterns. You can then make a plan to manage flares and avoid any triggers.