“Fatigue is one of the most vexing symptoms for people with Crohn’s disease,” says James Marion, MD, a professor of gastroenterology who specializes in Crohn’s disease at Mount Sinai Hospital in New York City. “It can be underappreciated by doctors and very frustrating for patients.” Case in point: A study published in March 2016 in the Journal of Crohn’s and Colitis found that a lack of energy is the most burdensome symptom for people with inflammatory bowel disease (IBD). Other research, published in January 2016 in the same journal, has found that more than 80 percent of people with IBD, including Crohn’s disease, report having debilitating fatigue. Follow these tips to start feeling better. Here are a few causes of fatigue in people with Crohn’s.

1. Lack of Sleep

During a Crohn’s disease flare, it can be difficult to eat and sleep well, which can make you tired, says Dr. Bloomfeld. “Chronic abdominal pain and frequent trips to the bathroom at night can disrupt sleep, which only compounds the problem,” adds Dr. Marion. The good news is that treating your underlying condition will likely help boost your energy.

2. Emotional Distress

Inflammation and pain linked to flares can cause emotional distress and make you more tired. In fact, anxiety and depression are commonly linked to Crohn’s, and both depression and stress can make you feel fatigued, says the Mayo Clinic.

3. Anemia

Another cause of fatigue related to Crohn’s disease could stem from nutritional shortfalls, particularly anemia. People with anemia don’t have enough healthy red blood cells to carry oxygen throughout their body, which can lead to fatigue, according to the Mayo Clinic. Anemia can be due to very low levels of vitamin B12 or iron, which your body requires to make red blood cells. Vitamin B12 is usually absorbed in the end of the small bowel (ileum), where Crohn’s disease activity often occurs.  A study published in June 2014 I the journal Inflammatory Bowel Diseases suggests that true vitamin B12 deficiency isn’t commonly linked to IBD, including Crohn’s disease. But if the ileum has been removed or altered by surgery, it may not absorb the vitamin as well as it should. The result can be anemia caused by vitamin B12 deficiency and, consequently, fatigue. In such cases, vitamin B12 shots may help, Marion says. A study published in March 2017 in the journal Nutrients showed that oral B12 medication has also been shown to be helpful in treating the deficiency in people with Crohn’s. Anemia due to lack of iron can also trigger fatigue. Since people with Crohn’s disease may lose blood via lesions in their small or large intestine, they may develop anemia, Marion says. You may also have a hard time eating enough iron-rich foods during a flare-up, so your doctor may recommend an iron supplement or injection to boost your intake. Some people need surgery to counter excessive blood loss.

4. Certain medications

Fatigue may also be related to certain medications for Crohn’s disease, according to the Mayo Clinic. Your doctor will likely do a complete workup to find out what’s causing your fatigue and troubleshoot it accordingly.

Tips to Reduce Crohn’s Fatigue

If your fatigue is linked to a Crohn’s disease flare-up, it’s essential to discuss your treatment options with your doctor. These may include changing the type or dose of medication you’re taking. And regardless of whether you’re having a flare-up, you may want to ask your doctor for a blood test to check your iron and vitamin B12 levels. If you’re deficient in either, they may recommend working with a nutritionist to adjust your diet and adding supplements or injections. No matter what’s causing your fatigue, it’s important to stay active, Bloomfeld says. The January 2016 study review suggests that exercise can help reduce IBD-related fatigue. Stretching, light exercise, and yoga are all good options to try, as they can help you build strength and boost energy. “It’s important to listen to your body, but you don’t need to stay in bed because of fatigue,” he says. Exercise can also help reduce depression and stress, which are often linked to fatigue and tend to go hand in hand with chronic illnesses like Crohn’s disease, according to the Crohn’s and Colitis Foundation. Plus, working out may also boost your immune system, the organization says. If you feel tired all the time, talk to your doctor to make sure you’re doing everything you can to treat all of the symptoms related to your Crohn’s disease, including fatigue. Additional reporting by Colleen de Bellefonds