Lupus develops when your immune system attacks your own tissues instead of protecting them

Lupus is not something you catch or contract. It is an autoimmune disease, which means your body's immune system mistakenly treats your own cells and tissues as threats and attacks them. This causes inflammation and damage in joints, skin, kidneys, heart, lungs, and blood cells. Why this happens in some people and not others involves a combination of genes you inherit, hormones in your body, and environmental triggers — but no single cause explains every case.

You cannot get lupus from another person, and you do not develop it from lifestyle choices or something you did wrong. It is not contagious. What matters is what you were born with and what your body encounters after birth.

Key Takeaways

  • Lupus occurs when your immune system attacks your own tissues; it is not contagious and cannot be caught from anyone else.
  • Genetics play a major role — lupus runs in families, though inheriting the genes does not may provide you will develop the disease.
  • Environmental triggers such as sun exposure, infections, certain medications, and stress can activate lupus in people who carry the genetic risk.
  • Hormones, particularly estrogen, influence lupus development, which is why the disease is far more common in women than men.
  • Having lupus in your family history increases your risk, but most people with a family history never develop the disease.

The role of genetics in lupus development

If a parent, sibling, or close relative has lupus, your risk of developing it is higher than the general population. Studies show that identical twins have about a 25 percent chance of both having lupus if one twin has it — meaning genetics matter, but they are not the whole story. You can inherit the genes that make lupus possible without ever developing the disease.

Researchers have identified multiple genes involved in lupus risk, not just one. These genes affect how your immune system regulates itself and how it responds to threats. Having these genes means your immune system is more likely to malfunction, but the malfunction does not happen automatically. Something else has to trigger it.

Environmental triggers that can activate lupus

Even if you carry lupus-related genes, the disease often does not appear until something in your environment sets it off. Sun exposure is one of the most common triggers — ultraviolet light can damage skin cells and cause your immune system to react abnormally. This is why people with lupus are advised to limit sun exposure and use high-SPF sunscreen.

Other environmental triggers include infections (particularly viral infections like Epstein-Barr virus), certain medications (such as hydralazine, procainamide, and some antibiotics), physical or emotional stress, and smoking. Pregnancy can also trigger or worsen lupus in some women. None of these triggers causes lupus on its own in someone without genetic risk, but in someone who carries the genes, they can be the event that tips the balance.

How hormones influence lupus risk

Lupus is diagnosed in women about nine times more often than in men, and this difference is largely driven by estrogen. Women have higher estrogen levels, and estrogen appears to amplify immune system activity in ways that increase lupus risk. This is why lupus often develops or worsens during reproductive years and may improve after menopause when estrogen levels drop.

Pregnancy is a particular time of change. Some women develop lupus during pregnancy or shortly after delivery. Others find their lupus symptoms worsen during pregnancy. The hormonal shifts that occur at these times can activate or intensify the disease in women who are genetically susceptible.

Why some people with the genes never develop lupus

The fact that identical twins do not always both have lupus, even though they share identical DNA, shows that genes alone do not determine whether you develop the disease. Many people carry lupus-related genes and never experience symptoms. They may never encounter the right combination of triggers, or their immune system may remain stable despite genetic risk.

This is important because it means having a family history of lupus does not mean you will definitely develop it. It means your risk is higher than someone with no family history, but most people with a family history remain unaffected throughout their lives.

What happens after lupus develops

Once lupus begins, it typically follows a pattern of flares and remissions. A flare is a period when symptoms worsen and inflammation increases. Remission is a period when symptoms improve or disappear. The triggers that caused the initial disease onset can also trigger flares — sun exposure, stress, infections, and stopping medications are common reasons symptoms return.

Lupus is a chronic disease, meaning it persists over time, but it is not progressive in the sense that it automatically gets worse. With treatment and management, many people control their symptoms and prevent organ damage. The course of the disease varies widely from person to person.

Frequently Asked Questions

Can I get lupus if no one in my family has it?

Yes. While family history increases risk, about 70 percent of people diagnosed with lupus have no known family history of the disease. Lupus can develop in anyone, though it is less common in people without genetic predisposition. Environmental triggers and other factors can activate lupus even without a family connection.

If my mother has lupus, will I definitely get it?

No. Having a parent with lupus increases your risk, but most children of people with lupus never develop the disease. You may carry the genes without ever experiencing symptoms. Risk is higher, but it is not certain.

Can stress alone cause lupus?

Stress can trigger lupus in someone who is genetically susceptible, but it cannot cause lupus in someone without that genetic risk. Stress is one of several environmental factors that may activate the disease, not a standalone cause.

Does lupus get worse over time?

Lupus follows a pattern of flares and remissions rather than steadily worsening. Some people have long periods without symptoms, while others experience frequent flares. With proper treatment and management, many people prevent serious organ damage and maintain stable health.

Can men get lupus?

Yes, though it is much less common. Men account for about 10 percent of lupus cases. When men do develop lupus, it often appears later in life and may be more severe, possibly because they lack the hormonal factors that affect women.