Hormones are chemical messengers that regulate many bodily functions. Because 90 percent of people with lupus are females, researchers are investigating the relationship between lupus and the female hormone, estrogen.

While both male and female bodies produce estrogen, females produce more of the hormone than do males. Furthermore, many women experience an increase of lupus symptoms before their menstrual periods and during pregnancy, when estrogen production increases. While this may suggest that estrogen somehow regulates the severity of lupus symptoms, researchers have not yet proven an association between lupus and estrogen – or any other hormone. Furthermore, studies of women with lupus who take estrogen in the form of birth control or treatment for menopause do not show that estrogen affects the severity of lupus symptoms. Scientists are now focusing on other differences between male and female physiology to determine why women are more prone to lupus and other autoimmune diseases than are men.

Lupus often runs in families, but it can develop in individuals with no family history of the condition. However, their family members are likely to have other autoimmune diseases.

Medical scientists have now identified more than 50 genes associated with lupus. These genes are more commonly present in people who have lupus than in those without the condition. While these genes do not cause lupus directly, researchers think the genes contribute to the development and severity of the disease.

Simply having the genes is not enough, though. There have been cases in which twins raised in the same environment and share inherited features have different outcomes – one twin develops lupus and the other does not. When one of the two babies has lupus, there is a higher likelihood that the other sibling will also develop the condition – there is a 30 percent chance of this happening for identical twins, whereas there is a 5 to 10 percent chance for non-identical, or fraternal, twins.

People of certain ethnic groups, including those of African, Hispanic/Latino, Asian, Native American, Pacific Island, or Native Hawaiian descent, have a greater risk of developing lupus. This may be due to genes shared between these groups.

Environmental factors, such as viruses or chemicals, may trigger lupus in those genetically prone to the condition. Researchers are still working to identify the specific environmental agents that may contribute to the development of lupus, but the environmental elements may include ultraviolet light infections, and exposure to silica dust in industrial or agricultural settings.

Other environmental triggers may include:

• Ultraviolet (UV) rays from the sun or fluorescent light bulbs
• Sulfa drugs that increase photosensitivity, such as Bactrim® and diuretics, also known as “water pills”
• Minocycline (Minocin®) and other tetracycline drugs
• Penicillin or other antibiotics, including amoxicillin (Amoxil®), cloxacillin (Cloxapen®), and ampicillin
• Infections, colds or other viral illnesses
• Exhaustion
• Extreme emotional stress, such as illness, divorce, death in the family, or other traumatic life events
• Anything else that causes physiological stress, such as surgery, injury, physical harm, pregnancy, or giving birth

Early diagnosis can help patients begin identifying triggers for the disease and start treatment regimens to prevent or control flares. Avoiding triggers, such as excessive exposure to the sun and stress, can help. Seeing a rheumatologist, who is a doctor specializing in conditions affecting the muscles, joints, and bones, can help. Rheumatologists can also tailor a treatment plan for each patient, and prescribe medications to slow the progression of the disease. Treatment focuses on lessening symptoms and reducing flares.