• Ulcerative colitis affects the colon and rectum, yet people with this condition or another type of IBD often have complications elsewhere in their body, too.
  • Some research has found that certain underlying factors may increase the risk for both ulcerative colitis and thyroid disease, but further research is needed.
  • Ulcerative colitis is not thought to cause thyroid disease or vice versa.

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) that causes inflammation in the colon and rectum.

Yet, those aren’t the only organs that can be impacted when you have UC. The Crohn’s and Colitis Foundation estimates that between 25 percent and 40 percent of people with IBD have complications in other parts of the body, such as the:

  • eyes
  • joints
  • bones
  • liver
  • kidneys
  • skin

An association may also exist between UC and trouble with the thyroid, a butterfly-shaped gland located in your neck, right above your collarbone. The thyroid uses hormones to control your metabolism.

While there’s no conclusive evidence that UC causes thyroid disease (or vice versa), research from 2018 has suggested that underlying factors may increase your risk for both conditions.

Keep reading to learn more about the potential link between UC and thyroid disease.

The exact link between UC and thyroid disease remains unclear. However, some studies have suggested that certain underlying factors may be behind both conditions.

A 2016 literature review, which looked at research going back several decades, found conflicting evidence on the rates of two common types of thyroid disease — hyperthyroidism and hypothyroidism — among people with UC or Crohn’s disease.

Hyperthyroidism is when the thyroid makes too much hormone, while hypothyroidism is when the thyroid doesn’t produce enough.

Some studies in that review found higher rates of thyroid disease among people with UC than among the general population. On the other hand, some studies in the report discovered no significant difference in the rates of the condition, or even found lower rates of thyroid disease among people with IBD.

That said, more recent research has uncovered potential ties between UC and thyroid disease. For example, a 2017 study from Taiwan found that 4.1 percent adults who have UC were previously diagnosed with hyperthyroidism, compared with 2.66 percent of adults in the control group.

Graves’ disease is the most common cause of hyperthyroidism, according to the National Institute of Diabetes and Digestive and Kidney Diseases.

It may be connected to genetic abnormalities, overgrowth of intestinal bacteria, and overactive immune systems that are also prevalent among some people with UC, according to notes from a 2017 clinical trial.

Congenital hypothyroidism, another type of thyroid disease, may be connected to similar underlying factors behind UC, according to a 2018 study. Researchers found that people with congenital hypothyroidism were more likely to have IBD and certain genetic abnormalities or mutations than the control group.

Research on the possible connection between thyroid disease and UC is ongoing, and further study is needed before experts can draw any firm conclusions.

Research hasn’t found that UC causes thyroid problems, or vice versa.

Instead, some common underlying factors may exist behind the two conditions. These may include:

  • an imbalance in the immune system
  • genetic mutations
  • an overactive thyroid
  • an overgrowth of bacteria in the intestines

It’s possible to have both thyroid concerns and UC at the same time. Talk with a healthcare professional if you have UC and experience symptoms of thyroid disease.

According to the Office on Women’s Health, these symptoms may include:

  • weight loss or gain without a change in diet
  • feeling cold or hot when others don’t
  • pain in your joints or muscles
  • constipation or diarrhea
  • muscle weakness
  • changes in menstruation, such as a lighter or heavier flow
  • puffy face
  • increased sweating
  • sleep concerns
  • trembling in your hands
  • feeling nervous, anxious, irritable, sad, or depressed
  • skin that’s dry or paler than usual
  • dry, thin hair
  • changes in heart rate

There’s no cure for UC or thyroid disease, but there are ways to treat and manage both conditions to help improve your quality of life.

Ways to reduce the risk of UC flares include:

  • medications (such as biologics, corticosteroids, or immunomodulators)
  • surgery to remove the colon (in cases where medication doesn’t work)
  • diet changes and avoidance of trigger foods
  • stress reduction techniques (like physical activity, yoga, and breathing exercises)

Treatments for thyroid conditions depend on which disease you have. You may need to take medication, undergo radioiodine therapy, or get surgery to remove some or all of your thyroid, among other potential treatments.

A doctor can provide personalized treatment recommendations if you have UC, thyroid disease, or both.

Clinical trials may continue to investigate links between thyroid disease and UC, as well as treatments that could help both conditions.

Participating in a clinical trial could give you the opportunity to try new treatments for your conditions. However, there are risks involved, too.

You may receive the standard treatments or a placebo, and you may experience side effects. That’s why it’s important to weigh the potential downsides and benefits before signing up for a clinical trial.

If you’re interested in getting involved in a clinical trial for UC and thyroid conditions, talk with a doctor to see if they know about upcoming studies. You can also search for clinical trials through the U.S. National Library of Medicine or the Crohn’s and Colitis Foundation.

While some people with UC also have a type of thyroid disease, the link between the two conditions is not yet clear. Doctors don’t believe that UC causes thyroid disease, or vice versa.

However, there may be an underlying factor (such as a genetic abnormality) that increases the risk for both conditions.

If you have UC and experience symptoms of a thyroid condition, talk with a doctor. They may have your thyroid function tested to see how well the organ is working.

While there’s no cure for UC or thyroid disease, medications and other treatments can help you manage the conditions and reduce your symptoms.