Ankylosing spondylitis is a rare type of arthritis of your spine that causes inflammation between your vertebrae. Its cause still is not entirely clear, although it does seem to run in families. It affects an estimated 1 in 200 people, according to research.

Keep reading to learn about the risk factors for developing ankylosing spondylitis and what you can do to decrease your chances of developing it.

The cause of ankylosing spondylitis is not clear, but a variety of factors seem to contribute to its development. Genetic and environmental factors both seem to play a role.

Family history and HLA-B27 gene

Having a family history of ankylosing spondylitis seems to increase your risk of developing it. Research estimates that about 90 percent of people with ankylosing spondylitis express the gene HLA-B27 versus less than 8 percent of people in the general population.

Carrying the HLA-B27 gene does not mean you’ll develop ankylosing spondylitis, but it may mean you’re more vulnerable to environmental factors that can contribute to its development.

More research is needed to understand why people with this gene are at an elevated risk of developing ankylosing spondylitis.

Other risk factors

Other risk factors for ankylosing spondylitis include:

  • Age. About 80 percent of people first develop ankylosing spondylitis symptoms under age 30.
  • Sex. Ankylosing spondylitis tends to develop about twice as often in men than in women.
  • Ethnicity. The prevalence of the HLA-B27 gene seems to vary between ethnic groups. According to one study, its incidence rate was 7.5 percent in non-Hispanic whites, 4.6 percent among Mexican-Americans, and 1.1 percent among non-Hispanic blacks.
  • Gut inflammation. Up to 70 percent of people with ankylosing spondylitis have gut inflammation, suggesting a potential origin in the gut. It’s thought disruption to the microbiome in your gut may play a role in its development.
  • Smoking. Some research has found an association between the development of ankylosing spondylitis and smoking, but the association still is not clear.
  • Childhood infections. A 2016 studyfound an association between childhood respiratory infections and the later development of ankylosing spondylitis. Childhood appendicitis was linked to a decreased risk.

You cannot prevent ankylosing spondylitis entirely because its exact cause is not known, and some of the risk factors are out of your control. Adopting health-promoting lifestyle habits like the following may help decrease the chances of developing it or slow its progress.

Here are some healthier habits you can follow:

  • avoiding smoking if you smoke
  • maintaining a moderate body weight
  • staying as physically active as possible to help improve your posture and range of motion
  • eating a nutrient-rich balanced diet to help improve your overall health, including helping you maintain a moderate weight
  • practicing good posture when standing and sitting
  • engaging in activities that help relieve stress, such as yoga, massage, or light exercise
  • applying a warm compress to loosen stiff muscles or joints as needed (15 to 20 minutes at a time)
  • applying a cold compress to reduce inflammation (15 to 20 minutes at a time)