Hyperthyroidism And Your Eyes: What You Need To Know

The thyroid helps every part of your body function properly, so when it isn't working at its best, it can lead to a wide range of symptoms.

One area that could be impacted is the eyes, with symptoms that range from mild to severe. For people with hyperthyroidism, it's important to pay attention to these symptoms.

What does the thyroid do?

At the lower front part of the neck sits the butterfly-shaped thyroid gland. This small-but-mighty gland is a part of the endocrine system, a network of glands that produce the many hormones your body needs to function.

The thyroid's part in this intricate system is making thyroid hormone, which is used in every tissue in the body and regulates many vital systems.

Thyroid hormone supports the function of the heart, brain, muscles, and all the other organs that are constantly working to keep you healthy. It also regulates all the functions that help your body stay warm and produce energy, collectively known as your metabolism.

The thyroid has a significant effect on how well the body works. This is good news when it's functioning as it should, but what happens when the thyroid misfires?

What is hyperthyroidism?

The thyroid gland can sometimes produce too much thyroid hormone for various reasons. This condition is known as hyperthyroidism, and it can have a dramatic impact on the body. According to the American Association of Clinical Endocrinology¹, this condition occurs in nearly 1% of all Americans, and it affects women five to ten times more often than it does men.

Because the thyroid hormone affects so many organs, the impact of this overproduction is felt all over the body. Instead of keeping your metabolism humming along at the right speed, an excess of thyroid hormone causes all of your systems to accelerate.

This can cause many different kinds of symptoms, including:

• Irritability

• Anxiety

• Heat intolerance

• Excessive sweating

• Hand tremors

• Muscle weakness, especially in the thighs and arms

• Rapid heartbeat

• Difficulty sleeping

• Unexplained weight loss

• Brittle hair

• Thinning skin

• Fewer and lighter menstrual periods in women

At first, people who develop hyperthyroidism usually feel extra energetic, but over time, the extra demands on the body lead to exhaustion. 

Does hyperthyroidism affect the eyes?

Since thyroid hormone is used in tissues all over the body, it's no surprise that hyperthyroidism can also affect the eyes.

People with hyperthyroidism may experience some irritation of the eyes' surface, caused by inflammation and changes to the tear film that protects them.

According to one study², signs of this damage to the eyes' surface can be detected in the early stages of thyroid dysfunction, whether the thyroid is over-producing or under-producing hormone. This damage can be detected even before you develop any symptoms of eye problems.

However, beyond this general irritation, a specific type of hyperthyroid disease sometimes affects the eyes. This condition, Graves’ eye disease, can cause many different symptoms, and they can be serious. 

Graves' eye disease

One cause of hyperthyroidism is an autoimmune condition known as Graves' disease. In people with Graves' disease, the body's immune system attacks the thyroid, causing an overproduction of thyroid hormone. In some cases, these immune system problems also affect the eyes.

People with Graves' disease produce antibodies that attack certain receptors on the cells of the thyroid, but they can also cause damage elsewhere.

The same antibodies can target receptors on the surface of tissues behind the eye, causing Graves' eye disease, also known as Graves' ophthalmopathy or thyroid eye disease.

When the tissues around the eyes are attacked, the resulting damage causes inflammation. This can make the eyes feel gritty or irritated, and the whites of the eyes may appear red and inflamed. The eyes may become sensitive to light, and they can be dry or produce excessive tears.

Some people experience pain behind their eyes and difficulty moving them. The inflammation can lead to blurred or double vision, and it can cause a change in the appearance of the eyes, causing them to bulge.

In advanced cases, it may become difficult to close the eyelids completely, even while sleeping. This can cause excessive dryness and lead to ulceration of the cornea. Rarely, the inflammation can press on the optic nerve, causing a loss of vision.

The problems caused by Graves' eye disease are different from the eye irritation that sometimes accompanies hyperthyroidism. Instead of a general irritation caused by hormone dysfunction, these symptoms are caused by the body's immune system directly attacking the tissues around the eyes. 

When should you see a doctor?

If you have any symptoms of hyperthyroidism, speak to your doctor right away. Whatever the cause of your condition, it's important to get diagnosed and seek treatment as soon as possible.

If you experience Graves' eye disease symptoms, you should also get that checked out, even if you haven't been diagnosed with Graves' disease. It is possible to develop Graves' eye disease without ever experiencing hyperthyroidism at all.

On the other hand, people who have Graves' disease can develop eye symptoms months or even years after their initial diagnosis and treatment.

There are treatments available for Graves' eye disease, ranging from eye drops to surgery, and the sooner you address the problem, the better. Your doctor will explain your options and help you figure out the best plan for your condition.

The lowdown

The thyroid supports systems all over the body, so hyperthyroidism can cause various effects. One of the symptoms it sometimes causes is eye problems, and if hyperthyroidism is caused by an autoimmune condition, these problems can become serious.

If you have an overactive thyroid, it's important to pay attention to any changes in your eyes and seek treatment.