Fatigue and ulcerative colitis: Understanding the many causes

Fatigue — feeling physically or mentally tired even after you rest — is one of the most common and least understood symptoms of ulcerative colitis (UC). For many people, fatigue is just as hard to live with as diarrhea or abdominal pain because it often continues even when bowel symptoms are well managed. Instead of a single cause, fatigue with UC is usually the result of a combination of factors. Here’s what you need to know.

Fatigue with ulcerative colitis is often caused by chronic inflammation that is part of the disease itself. When inflammation is ongoing and the immune system stays active, even at low levels, it uses energy and sends out signals that can affect the brain and nerves. This can cause you to feel tired even when your digestive symptoms are mild or not noticeable. In some cases, feeling tired may be the only sign that the disease is active, so it's important to tell your healthcare professional if you have low energy.

People with UC have a higher risk of anemia, a condition in which the body doesn't have enough healthy red blood cells to carry oxygen. Chronic inflammation in the gut and intestinal blood loss can cause iron-deficiency anemia, the most common type of anemia. Iron helps red blood cells carry oxygen throughout the body. Not having enough iron or being anemic can make you feel tired or weak, cause shortness of breath, and make it difficult to focus.

Ulcerative colitis can make it hard to get the nutrition your body needs. Not getting enough calories or protein can drain energy. Plus, reduced appetite, limited food choices, problems absorbing nutrients and the extra energy your body needs during flares can lead to nutritional deficiencies that cause fatigue. Low levels of iron and vitamin D are common in UC and contribute to feeling tired, muscle weakness and low stamina.

Sleep problems are another common cause of fatigue for many people with ulcerative colitis. Nighttime symptoms such as diarrhea, urgency, abdominal pain or cramping can repeatedly wake you up and prevent deep, restorative sleep. Over time, poor sleep causes ongoing tiredness and makes it hard to function during the day.

Fatigue that's linked to mood or stress is real and not a matter of motivation. Stress and low mood can contribute to feeling drained of energy. Plus, living with a chronic, unpredictable condition like UC can increase the risk of anxiety and depression. Both can cause ongoing tiredness. Stress also can make sleep problems worse and increase inflammation, creating a cycle where emotional strain and physical exhaustion feed each other.

Fatigue is sometimes a side effect of certain medications. Or it may be caused by other medical conditions unrelated to UC. Thyroid conditions, abnormal blood sugar levels and other illnesses can reduce your energy. Instead of assuming ulcerative colitis is causing your fatigue, tell your healthcare team that you feel tired so they can check whether a medication or another health issue is responsible.

It's important to tell your doctor or healthcare team if you feel worn out or if fatigue is getting worse. A thorough checkup can help determine whether fatigue is due to active inflammation, a correctable deficiency or another health condition. Recognizing fatigue as a real and common symptom — and understanding its many causes — is an important step toward improving your health and quality of life.