8 Surprising Ways Crohn's Affects Your Body

Arthralgia, or joint pain, affects up to a third of people with Crohn’s, according to research in the journal Gastroenterology & Hepatology. It can show up anywhere, but it’s most common in smaller joints—think wrists, knees, and ankles. Doctors aren’t sure why. “One theory is that the inflammatory drive that leads to intestinal inflammation overlaps with an antigen that is commonly present in the joints—or vice versa,” says study author and gastroenterologist David T. Rubin M.D., co-director of the Digestive Diseases Center at UChicago Medicine.

We mostly think of osteoporosis as an issue for post-menopausal women, but 30% to 60% of people with Crohn’s—some in their 20s and 30s—may have bone-density issues, according to the Crohn’s and Colitis Foundation. It’s almost certainly multifactorial, says gastroenterologist Raymond K. Cross, Jr., M.D., director of the IBD Program at the University of Maryland Medical System. The inflammatory response itself can produce molecules that have a negative effect on bones. Or there could be reduced absorption of calcium and vitamin D due to the disease.

For people with severe Crohn’s who aren’t getting outside much, vitamin D deficiency could also be an issue—and your body needs D to help with calcium absorption. Another contributor to bone loss: Corticosteroids, especially those taken long-term. If you’re worried about your bone health, ask your doctor to test your vitamin D levels, and request a bone-density scan if you fall into one of the following categories: You have accumulated more than 90 days of steroid use; you’re female and post-menopausal; or you have a history of bone fractures.

A lesser-known symptom of Crohn’s, eye inflammation can manifest itself in a few ways, including iritis, or swelling in the colored ring around the pupil. A study from the University of Manitoba in Winnipeg, Canada, found that iritis affects 2.2% of women and 1.1% of men with Crohn’s. Uveitis is another type of inflammation that can happen if you have Crohn's. It affects the middle layer of tissue in the eye wall. Redness and pain are some of the common signs, and it can lead to sight degeneration if left untreated.

“There are several skin manifestations associated with IBD, but the most common is called erythema nodosum,” says Dr. Kinnucan. “This is the presence of painful, red or purple bumps on the front of the legs, typically located below the knees; however, they can also be found on other parts of the body.” The condition, which can happen due to underlying inflammation in the intestines, is an important signal that there’s something happening in the GI tract—even if you don’t have obvious Crohn’s symptoms yet.

For reasons medical experts are still sorting out, having Crohn’s raises your risk of blood clots. So during a severe flare—when your one wish is lie still and not move a muscle—that’s the exact opposite of what you should be doing. Inactivity and lying horizontally can increase your risk of blood clots (or venous thromboembolism) even more, Dr. Kinnucan says. If your flare lands you in the hospital, your doctor may want to give you a shot of blood thinners to prevent clotting.

Depressive symptoms are present in 49% of people with IBD, versus 23% in those without, according to researchers from the Medical College of Wisconsin who gathered data from 192 million people. Being older, divorced, separated, or widowed all ticked up the odds of depression. And yet, only 36% of these people had seen a mental health professional for treatment in the past year. If this describes you, consider talking to a therapist—Crohn’s isn’t easy, but it’s easier when you have support.

“Sometimes, people change their diet to combat the disease, but it compromises their nutrition,” says Dr. Cross. “Or it could be that the disease causes parts of the GI tract that would normally absorb nutrients to malfunction and not absorb them properly.” Either way, poor nutrition can cause your energy to sag. It’s natural to avoid foods that might trigger a flare, but if you rack up enough foods on your no-go list, you could be setting yourself up for malnutrition. Work with your gastroenterologist to find a healthy food balance.

When Crohn’s kicks in, stress goes up. That creates a nasty feedback loop, since stress can make flares worse. Certain relaxation tricks can help, says Dr. Cross. Start by getting a restful night’s sleep and practicing mindfulness and breathing exercises. Also, “IBD patients who exercise regularly have reduced pain scores and improved quality of life,” Dr. Kinnucan says. “And patients who practice yoga regularly have reported reduced joint pain.” Whether or not om’s your thing, try making time each day for a stress-relieving moment.