Hashimoto’s Thyroiditis and Thyroid Eye Disease

If you have been diagnosed with thyroid eye disease (TED), you may or may not have problems with your thyroid. Despite its name, TED can occur in those with a normally functioning thyroid. However, this is more unlikely, and many people with TED have problems with their thyroid.¹

Most people with TED have an overactive thyroid (hyperthyroidism). However, some might have an underactive thyroid, known as hypothyroidism. The most common cause of hypothyroidism is Hashimoto’s thyroiditis.¹

Knowing about Hashimoto’s can help guide your treatment options for TED.

What is Hashimoto’s thyroiditis?

Thyroiditis means inflammation of the thyroid gland. In Hashimoto's thyroiditis, the body cannot tell the difference between healthy and harmful cells in your thyroid. As a result, the immune system targets healthy cells in the thyroid and attacks them. This leads to inflammation.²

The result is underactive thyroid function, or hypothyroidism. Hashimoto’s thyroiditis is also called Hashimoto’s disease.²

Autoimmune conditions occur when the immune system cannot recognize healthy cells from unhealthy ones. Because of this, the immune system attacks the healthy cells, causing damage. Hashimoto’s disease is an autoimmune condition.³

Symptoms of Hashimoto’s disease

The onset of symptoms may be mild and happen over time. This can make it hard to recognize the symptoms of Hashimoto’s disease at first. The signs and symptoms of the disease are mainly those of hypothyroidism.²

Signs and symptoms of low thyroid function include:²

• Puffy face
• Fatigue
• Constipation
• Dry, brittle nails and hair
• Unexplained weight gain
• Muscle aches and joint pain
• Depression
• Memory problems

Thyroid eye disease and Hashimoto’s disease

Like Hashimoto’s disease, TED is also an autoimmune condition. In TED, the immune system attacks the healthy tissues behind and around the eyes. The result is symptoms of TED, which include:¹

• Swollen, red eyes and eyelids
• Bulging eyes
• Dry, gritty, irritated eyes
• Watery eyes
• Double or blurred vision
• Pain behind the eyes, especially when looking sideways, up, or down
• Pain with bright lights

Research has shown that people with TED are more likely to have other autoimmune conditions. The exact reason for this is still unknown. However, doctors think certain genes are passed on through families.¹

About 1 in 15 people with Hashimoto’s disease also have TED.⁴

Diagnosing Hashimoto’s

Based on your signs and symptoms, your doctor can order blood tests to diagnose Hashimoto’s. These may include:⁵

• Thyroid-stimulating hormone – If you have an underactive thyroid, your thyroid hormone level is low. At the same time, your thyroid-stimulating hormone (TSH) level is high. This is because the pituitary gland in your brain stimulates your thyroid gland to make more thyroid hormones.
• Thyroid peroxidase – Harmful antibodies that attack the thyroid are present in those with Hashimoto’s. A blood test can confirm the presence of these harmful antibodies, known as thyroid peroxidase (TPO antibodies). However, having TPO antibodies does not confirm Hashimoto’s. Some people with Hashimoto’s do not have a positive TPO test. Still, others have TPO antibodies and do not have Hashimoto’s.

What does this mean for you?

Hashimoto's disease and TED are not the same. Both conditions are distinct disorders that require different therapies.

If you have abnormal thyroid function, your doctor will want to normalize your thyroid hormone levels. Hypothyroidism might require thyroid hormone replacement therapy. However, this is not always the case. Also, TED symptoms are often not improved even after normalizing thyroid function. Because everyone responds differently, this complicates treatment options.⁶

Talk to your doctor about your risks for TED. Of course, everyone is different, but asking about concerns or symptoms should be brought up at your visits.

If you have been diagnosed with TED, search for an eye doctor who is experienced in treating it. TED specialists are eye doctor experts in diagnosing, treating, and managing TED.

If you believe that your thyroid gland is functioning abnormally, speak with your doctor right away. Your primary doctor might refer you to an endocrinologist. These doctors are experts in hormones and regulating thyroid function. Together, you and your doctor can come up with a plan to help you manage both TED and Hashimoto’s.⁶