To diagnose thyroid eye disease (TED), a doctor must examine your eyes to identify signs such as bulging or swelling. A CT or MRI scan may be necessary, along with bloodwork, to examine your thyroid function.

TED is an autoimmune disease that damages the thyroid, a gland at the front of your neck. This causes an overproduction of thyroid hormones, which is why TE is associated with hyperthyroidism.

Eye symptoms such as bulging or inflammation can also occur because the immune system mistakenly targets tissue behind the eyes, causing TED.

TED can develop as part of different conditions that affect the thyroid gland. About 90% of cases occur as part of Graves’ disease, in which case it is called Graves’ orbitopathy or Graves’ ophthalmopathy.

Around a third of people with Graves’ disease will develop symptoms. In 5% of cases, people get moderate-to-severe eye inflammation, causing serious or permanent vision changes.

A doctor will usually suspect TED based on your symptoms and after examining your eyes.

To confirm the diagnosis, they may want to measure the amount of bulging in your eyes, evaluate your visual field and color vision, or order a CT or MRI scan of your eye sockets and muscles.

They may also want to look at how the blood flows in your eyes with Orbital Color Doppler Imaging (CDI).

Finally, they may want to see how your thyroid works, which they can evaluate based on a blood test.

When to get urgent care

See a doctor immediately if you notice:

  • double vision
  • blurry vision
  • difficulty moving your eyes
  • blindness (rare)

Learn more about vision problems in TED.

TED is most likely to occur within 18 months of a diagnosis of Graves’ disease. However, TED can occur in Graves’ patients with healthy or even low thyroid levels.

TED can also occur with Hashimoto’s thyroiditis, a hypothyroid condition. TED isn’t directly linked to high thyroid levels.

Sometimes, TED is the first sign of any thyroid problem. However, higher thyroid levels won’t cause a more severe case of TED

Autoimmune diseases remain a mystery. It’s unclear what causes the body to attack healthy cells, though there are some possible risk factors.

For TED, these include:

You may have different specialists involved in your care. It will depend on the presence and severity of any eye symptoms.

You may already be working with an endocrinologist to manage your thyroid condition. An endocrinologist specializes in hormones, including those produced by the thyroid. You’ll have regular blood work to monitor your thyroid levels.

If you have signs and symptoms of TED, an eye specialist can help. You may be referred to an ophthalmologist. This kind of eye specialist can help if further treatment or surgery is needed.

Can hypothyroidism cause thyroid eye disease?

TED is much more closely associated with hyperthyroidism than hypothyroidism. It occurs in only 6% of cases of Hashimoto’s Thyroiditis compared to about 25% of people with Graves’ disease.

After a diagnosis of Graves’ disease, it can take time to manage thyroid hormone levels. Sometimes, treatment for Graves’ disease causes thyroid levels to drop too low. Close monitoring of thyroid levels is important in managing Graves’ disease.

Symptoms of TED may also occur before a diagnosis of Graves’ disease.

What are the first signs of thyroid eye disease?

If you have Graves’ disease, your healthcare team may tell you to watch for any changes in your eyes. In some cases, TED is the first sign of hyperthyroidism. However, it can occur when thyroid levels are high, normal, or even in the low range.

Signs and symptoms of TED include:

  • eye swelling and redness
  • the sensation of grit in the eye, leading to excessive tearing
  • dry eyes
  • light sensitivity
  • eyelid swelling
  • changes in vision, including double vision
  • visual bulging of the eyeball
  • aching or discomfort in the eye when looking to the side or upward

Can an optometrist tell if you have thyroid eye disease?

An optometrist should be able to identify the first visual signs of TED during an eye exam, though they may have to refer you to an ophthalmologist or endocrinologist for confirmation.

Learn more about an optometrist vs an ophthalmologist.

What can be mistaken for thyroid eye disease?

Other conditions that may present with similar symptoms to TED include fracture of the eye orbit, lymphoma, and amyloidosis.

Around a third of people with Graves’ disease develop TED, but TED can also occur with other conditions. It is diagnosed by examining the eyes and performing a number of scans to identify the tell-tale signs, such as eye bulging and redness, often along with signs of an overactive thyroid gland.

The symptoms can include irritation, swelling, and a bulging appearance of the eyeball. Make note of any eye changes, and talk with your healthcare team if you have any concerns.