Lupus doesn’t have one clear origin. Researchers believe it comes from a complex equation of factors. One part of the equation is your genetic makeup. Another part involves the hormones that regulate much of your body’s functions. A third is your environment.

When scientists use the term “environment,” they don’t mean only sunlight and other outdoor factors. “When we start talking about the environment, we are talking about things that are nongenetic in nature,” explains Mark F. Gourley, M.D., fellowship training program director at the National Institute of Arthritis and Musculoskeletal and Skin Diseases at the National Institutes of Health (NIH).

Chemicals, diseases—even the ebb and flow of hormones—can all be thought of as environmental exposures.

Stress

In March 2005, Rachael Durrant-David went through a nasty breakup. At the same time, she was promoted to the more demanding position of scheduling officer at the hospital where she works in San Juan, Trinidad and Tobago. “It was a really tense time in my life,” she remembers.

She woke up one morning to find she couldn’t move. She was completely frozen in bed. “I didn’t know what happened, but something was definitely wrong,” she recalls. “It was just so scary.”

It took her four hours to get up and dress herself, a process that would have normally taken less than an hour. “I had to depend on a complete stranger to put me into a taxi. And then I had to depend on the driver to physically take me into the ER.”

Eventually, Durrant-David, now 33, learned that lupus was the reason for her sudden paralysis and lack of muscle control. Yet today, even though she’s being treated for lupus, the stress of her job can still bring on symptoms. “On Friday by the time I leave the office, I can feel the effects coming on,” she says. “And then by Saturday morning I’m ill—I’m flaring up.”

While stress probably doesn’t cause lupus, it certainly is a known trigger. “There are many studies that connect stress with immune reactions,” says Meenakshi Jolly, M.D., M.S., assistant professor of medicine and associate program director of the Rheumatology Section at Rush University Medical Center in Chicago. “We definitely do know that stress brings about flares of lupus.”

Toxic exposures

The environmental exposure that has one of the best-studied connections with lupus is silica. Silica is a mineral that people can be exposed to in mining and glass production. “Silica is one of the strongest known risk factors for the development of lupus,” says Frederick W. Miller, M.D., Ph.D., chief of the Environmental Autoimmunity Group at the NIH’s National Institute of Environmental Health Sciences (NIEHS). The problem seems to lie in the fine dust from rock or sand, or in products such as pottery, ceramics, or tile dust, according to Christine G. Parks, M.S.P.H., Ph.D., a research fellow in the Epidemiology Branch of the NIEHS.

The increased lupus risk is between two- and fivefold in those who have been exposed to silica at work, says Miller, who collaborated with Gourley on a review of environmental factors in lupus. Most of the risk noted in studies has been from work-related, not occasional, exposures—miners and farmers who were regularly exposed to silica dust on the job.

Work-related pesticide use has also been linked to lupus. Most of the studies have looked at people who worked with pesticides, particularly farmers and agricultural laborers. Recently, though, Parks discovered that even home pesticide use could be an influencing factor. “We found that more frequent or long-term use of insecticides, where you’re being directly exposed by spraying or mixing, was related to a higher risk of developing lupus and rheumatoid arthritis in the postmenopausal women we looked at,” she says.

Viruses and infections

In addition to looking at chemicals and other substances in the environment, researchers have homed in on a possible lupus-virus link. In particular,  Epstein-Barr, the virus that causes mononucleosis. Normally when people are exposed to a virus such as Epstein-Barr, their immune system produces antibodies to fight it off. That process doesn’t seem to work the same way in people with lupus, who produce different antibodies to the virus.

“It might be that the immune system of a person with lupus reacts differently when it is exposed to a virus than does the immune system of a healthy individual,” Gourley says. “In this case, someone with lupus may have an unusual immune response to the Epstein-Barr virus, which causes the immune system to do something it’s not supposed to do.”

See also: Preventing yourself from infection

Household chemicals

With other suspected lupus triggers, the evidence still isn’t clear. Hair dye, for example, has been blamed for conditions ranging from cancer to birth defects. As with these conditions, hair dye’s link to lupus doesn’t hold up to research scrutiny. “I scoured the world’s literature, and I looked only for studies that were controlled,” Gourley says. “Most studies fail to find evidence that hair dye increased the chance of developing lupus.”

Whether solvents (found in paint thinners, nail polish, and glue) cause lupus is also unclear. A few animal studies have found a connection between solvents and lupus. Yet, human studies have been less consistent, Parks says.

Identifying your environmental triggers

As with solvents, the research on triggers of flares is incomplete. Yet those experiencing frequent flares say they have all the evidence they need.

People with lupus can trace their symptoms to a number of lifestyle triggers. Some women experience flares right around their menstrual cycle. Others say they pay for every steak dinner and glass of wine with pain. For others, it’s stress.

Evidence exists to back up at least some of these claims. For example, it makes sense that women with lupus have symptoms right around their monthly cycle, because estrogen—the female hormone—regulates certain cells that help the immune system communicate with the rest of the body. As for red meat and alcohol, both increase uric acid levels in the blood. Uric acid leads to joint pain in people with gout, an arthritic condition.

Red meat is one of the things Alysia Nunnally, 35, has had to cut back on because of her lupus. She also has to stay indoors as much as possible during the summer months, because the heat and ultraviolet (UV) rays from the sun in Snellville, GA, are too much for her body to take. “If the sun is shining on me, it gives me fatigue,” says the stay-at-home mom. “Just walking from the door to the car sucks my energy away.”

Experts say humidity can provoke joint soreness, while exposure to the sun’s UV rays seems to throw the immune system off balance. “Ultraviolet B rays can cause certain cells in the skin to give immune signals,” Gourley says. Those signals attract white blood cells, which attack and destroy skin cells. That’s why a severe sunburn can lead to inflammation and a rash. Sun exposure also hastens the natural process of cell death, called apoptosis, by killing off more skin cells than normal.

Stress is something that people with lupus, like Durrant-David, cite over and over as a source of their symptoms. However, it’s hard to scientifically prove the effects of stress on the disease. “I think there’s a really solid rationale for why stress could trigger and worsen autoimmune diseases, but it’s very difficult to study because there are so many different kinds of stress,” Parks says. “But it’s plausible that stress can affect the immune system.”

Controlling your triggers

Researchers still have much to learn about what causes lupus and what provokes its symptoms. “We don’t really have a good way of knowing what we’ve been exposed to on a daily basis,” Miller says. And many of the known lupus suspects are hard to avoid. Working in the garden can expose you to pesticides or chemicals, but you can’t pinpoint exactly how much exposure you’re getting. The Epstein-Barr virus hides in almost everyone’s body, but most people have no idea they’ve been infected.

Other lupus triggers are easier to control, especially if you practice good prevention on a daily basis. “Do the things your mother told you to do—eat right, sleep right, and exercise,” advises Gourley. “I think that’s just common-sense living.” Avoid the sun or wear a sunscreen with UVA/UVB protection and an SPF of at least 35 when you go outside. Don’t smoke, because in addition to causing cancer, cigarettes can make lupus more active. When you’re feeling stressed out, try relaxation techniques like meditation or yoga.

If you’re not sure what’s behind your flares, Miller suggests keeping a diary. Whenever you have symptoms, write down where you were and what you were doing or eating.

J. Dawn Miller, 34, has been keeping a health journal for most of the seven-and-a-half years since she was diagnosed with lupus. “In the beginning I was tracking my symptoms from day to day. Over time, you start to notice patterns,” she says.

One of her patterns comes and goes with the weather. “I live in Ohio, and when it’s cold and wet, that’s my nemesis,” she says.

Miller also noted in her diary the flares that would pop up just before her period the pressure that would creep into her shoulders and chest right after she ate meat or certain cheeses. Miller, a new mom, has learned to adjust her habits as needed and take better care of herself. Yet, she’s also realistic enough to know that any change in her lifestyle—no matter how substantial—won’t completely erase her lupus.

“The one thing I realized in looking at those patterns was that, regardless of how much I cut out or how much I change, I’m still going to have flares. You can only limit yourself so much. You don’t want to stop living life,” she says.

Durrant-David also has found ways to manage—if not completely alleviate—her stress, in part by becoming more detached from her job. She also finds prayer to be an effective coping mechanism. “[With prayer], I feel really calm. I feel relieved. For that moment, even a few hours, I feel as if I’m free,” she says.