Fibromyalgia & Hashimoto's Thyroiditis

Similar, with Important Differences

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Pain in the neck, hips, knees, hands, and feet. Getting cold a lot. Being tired all day. Brain fog. Problems swallowing. These symptoms are just par for the course when you have fibromyalgia.

But those of us with these conditions need to be aware of another possible source of those symptoms, especially if they get significantly worse or don't seem connected to our other fibromyalgia symptoms: Hashimoto's autoimmune thyroiditis, which is also called autoimmune thyroid disease.

What is Hashimoto's Autoimmune Thyroiditis?

In autoimmune disease, your immune system goes haywire and thinks that normal tissues are actually dangerous invaders, like virus or bacteria, and works to destroy them.

In Hashimoto's, the immune system has decided a particular protein in the thyroid gland is a foreign invader. It then forms antibodies that begin to attack the gland—which is in your neck—and destroy it.

Hashimoto's is one of the most common autoimmune diseases. About ten percent of the population has it. 

Typically, people don't know anything is wrong until their thyroid is so damaged that it impacts thyroid-hormone levels, and typical treatment means taking thyroid hormone to normalize levels. Sometimes, doctors will prescribe medication to help manage the pain, inflammation, and other symptoms, as well.

The thyroid gland puts out hormones that regulate a lot of important things, including:

  • metabolic rate
  • heart function
  • digestion
  • muscle control
  • brain development

Essentially, the thyroid's job is to make sure all of your organs are working properly. So when your body tries to destroy it, a lot can go wrong.

Symptoms of Hashimoto's include:

  • fatigue
  • sluggishness
  • constipation
  • pale, dry skin
  • puffiness in the face
  • hair loss
  • increased cold sensitivity
  • brittle fingernails
  • swelling in the tongue
  • muscle/joint inflammation, pain, and stiffness
  • muscle weakness
  • unexplained weight gain
  • memory lapses
  • depression
  • long and/or heavy periods

Again, there's a lot of overlap with fibromyalgia symptoms, so it's important to look for changes in your symptom patterns and keep an eye out for those symptoms that aren't part of fibromyalgia.

The type of pain experienced with Hashimoto's may be quite different from fibromyalgia pain. Rather than the burning, stabbing pains that move around the body, Hashimoto's may cause a deep ache. Hashimoto's pain is most commonly in the neck, hips, knees, hands, and feet.

Hashimoto's & Fibromyalgia

Research suggests that Hashimoto's may be a cause of fibromyalgia. We also know that fibromyalgia appears to predispose people to autoimmune diseases, so it may be that no matter which one comes first, it raises your risk of the other.

Multiple studies have shown that the antibodies linked to Hashimoto's are found in people diagnosed with fibromyalgia more often than in the general population, even among those who don't have low thyroid hormone levels.

Whatever the relationship, it's generally accepted in the medical community that some relationship exists.

That means it's important for doctors and patients to consider the possibility of more than one diagnosis, especially when all of the symptoms aren't consistent with one condition or the other.

Other Thyroid Disease in Fibromyalgia

Other thyroid disease is also common with this condition, especially hypothyroidism, which involves low thyroid hormone levels but is not autoimmune like Hashimoto's.

Because Hashimoto's and hypothyroidism both involve low thyroid hormone levels, most of their symptoms are the same. However, hypothyroidism is not associated with inflammation, while Hashimoto's is.

Getting a Diagnosis & Treatment

If you suspect thyroid disease, it's important that you bring it up with your doctor and ask to be tested.

Low thyroid hormone levels can throw off a lot of crucial functions in your body, so you don't want to let Hashimoto's or hypothyroidism go untreated.

Sources:

Ahmad J, Blumen H, Tagoe CE. Association of antithyroid peroxidase antibody with fibromyalgia in rheumatoid arthritis. Rheumatology international. 2015 Aug;35(8):1415-21.

Ahmad J, Tagoe CE. Fibromyalgia and chronic widespread pain in autoimmune thyroid disease. Clinical rheumatology. 2014 Jul;33(7):885-91.

Bazzichi L, Rossi A, Zirafa C, et al. Thyroid autoimmunity may represent a predisposition for the development of fibromyalgia? Rheumatology international. 2012 Feb;32(2):335-41.

Nishioka K, Uchida T, Usui C, et al. High prevalence of anti-TSH receptor antibody in fibromyalgia syndrome. International journal of rheumatic diseases. 2016 Nov 30. [Epub ahead of print]

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