People living with ulcerative colitis (UC) are at an increased risk of developing anemia. Anemia can be serious, but is treatable.

UC is a form of inflammatory bowel disease that causes inflammation in the large intestine.

People with UC are at risk of developing anemia, a condition in which there are lower levels of red blood cells and the protein hemoglobin in the blood. This can be due to problems caused by UC, including reduced iron absorption, reduced absorption of other vitamins and minerals, and blood loss.

Learn more about the link between UC and anemia, including symptoms, treatment options, and long-term outlook.

People with UC are at risk of developing anemia. Roughly 1 in 3 people who live with UC also have anemia.

In UC and Crohn’s disease, another form of inflammatory bowel disease, inflammation in the intestine can prevent the body from absorbing iron properly. This can cause low iron levels, leading to anemia.

Intestinal bleeding may also result in blood loss, causing anemia. Anemia in people with UC could result from reduced absorption of vitamins and minerals, including vitamin B1 and folic acid. Some UC medications may also cause anemia.

Not everyone with anemia will experience symptoms, so it is important those with UC get a test for anemia.

If a person does experience symptoms of anemia, these may include:

  • headaches
  • lack of appetite
  • difficulty with concentration or cognitive function
  • irritability
  • fatigue
  • tingling in the hands or feet
  • numbness in the hands or feet
  • cold hands and feet

If anemia gets worse, more symptoms may develop. These include:

  • abnormal menstrual bleeding
  • ulcers in the mouth
  • blue-ish color in the whites of the eyes
  • brittle nails
  • lightheadedness
  • low libido in males
  • inflamed or sore tongue
  • shortness of breath

Doctors can diagnose anemia through a blood test to see if there are low levels of red blood cells and hemoglobin.

To diagnose anemia, a doctor may recommend tests for:

  • complete blood count
  • vitamin B12 levels
  • iron levels
  • folic acid levels
  • reticulocyte count, the amount of immature red blood cells in the blood

A doctor may also do a physical exam to check for:

  • rapid heart rate
  • pale skin
  • slight fever
  • heart murmur
  • low pressure, particularly upon standing

While anemia can be serious, it is also treatable.

Treatment options for anemia in people will UC will depend on the cause of the anemia and whether the UC is active.

A doctor will decide what treatment option is best, taking into account:

  • whether UC is active
  • whether other medical problems are present
  • whether other nutritional deficiencies are present

Iron supplements

Iron supplements are one option for treating anemia in people with UC.

People who have UC in remission can take iron supplements orally. If someone with UC is in remission and can tolerate foods with iron, doctors recommend they begin to incorporate those foods into their diet.

If a person has UC that is not in remission, they may need to receive iron via an infusion with an IV line. This may also be the best option for those who cannot tolerate oral iron supplements.

Other medications

A doctor may prescribe other supplements to counteract the reduced absorption of certain vitamins and minerals due to UC.

Supplements may include vitamin B12 and folic acid.

Blood transfusion

In some cases, doctors may use a blood transfusion to treat severe anemia.

Before a blood transfusion, a healthcare professional will test a person’s blood to identify their blood type.

They will then insert an IV line into a blood vessel to deliver healthy blood. Typically, a blood transfusion will take 1–4 hours to complete.

A blood transfusion helps increase the hemoglobin and oxygen levels in the blood.

Managing UC to treat anemia

Getting UC under control through appropriate treatment may help treat anemia. There is no cure for UC, but a multifaceted approach to treatment can help manage the disease.

Treatment options for UC may include:

  • Medications: Possible medications include aminosalicylates, corticosteroids, immunomodulators, targeted synthetic small molecules, and biologics. Medication can help limit flare-ups and reduce inflammation.
  • Diet: Working with a doctor or dietitian to avoid foods that aggravate the digestive system may improve symptoms.
  • Surgery: Between 25–33% of people with UC do not benefit from medical therapy. For these people, doctors may recommend a surgery such as a colectomy.

If a person is experiencing symptoms of anemia or unusual blood loss, they should call a doctor.

It is important for those living with UC to be aware of symptoms that may indicate a flare-up or worsening of the condition.

Symptoms that may indicate a change in a person’s condition and require a call to the doctor may include:

  • weight loss
  • loss of appetite
  • frequent, watery diarrhea
  • diarrhea that contains blood, mucus, or pus
  • pain in the abdomen
  • a sense of urgency to have a bowel movement
  • fatigue

Any sudden or severe symptom requires attention from a doctor. In some cases, certain symptoms may warrant an emergency call to the doctor or a trip to the emergency room.

These symptoms include:

  • new rectal bleeding
  • significant amounts of rectal bleeding
  • a drastic change in bowel movements without passing gas
  • persistent vomiting and no bowel movements
  • severe abdominal pain that persists for more than an hour
  • a high temperature

Those with ulcerative colitis (UC) are at risk of developing anemia due to reduced iron absorption and potential blood loss. Certain medications and reduced absorption of minerals may also play a role in those with UC developing anemia.

Not everyone with anemia will experience symptoms, and it is important those with UC get a blood test to check if they have anemia.

While anemia can be serious, it is treatable. Treating anemia may involve taking oral iron or intravenous supplements. Managing UC will also help in the treatment of anemia.