What Is Graves' Disease?

Graves' disease is the most common cause of hyperthyroidism (elevated levels of thyroid hormone) in the United States. Graves' disease is an autoimmune condition that indirectly causes the thyroid gland to release too much hormone. This can cause symptoms like a racing heartbeat and anxiety that may come and go. Rarely, it can also lead to potentially life-threatening symptoms like heart failure.

Graves' disease is named after Irish physician Robert Graves, who first described this form of hyperthyroidism in 1835.

Graves' disease affects roughly 1% of people, most commonly occurring between ages 30 to 50. Diagnosis involves distinguishing Graves' from some other less common causes of hyperthyroidism such as viruses, certain medications, and growths on the thyroid gland, among others. 

Fortunately, with multiple effective treatment options available, the outlook is good for people with this condition. Although, long-term management is needed.

Symptoms

The excess thyroid hormone that occurs with Graves' disease can affect multiple organ systems. Your symptoms can vary based on factors like your age and the severity of your hyperthyroidism. Most commonly, a person will have repeated episodes of symptoms, but sometimes symptoms are more constant.

Common symptoms may include:

• Weight loss, despite an increased appetite
• Tremor
• Excess sweating 
• Intolerance to heat
• Frequent bowel movements (but not diarrhea)
• Anxiety and jitteriness
• Fatigue and difficulty sleeping
• Goiter (lump in your neck)
• Rapid and uncomfortable pulse

About 25% of people also experience eye changes, like bulging eyes or swelling around the eyes, which may affect vision.

Cardiovascular Complications

In addition to rapid pulse, other heart problems from Graves' disease can be a concern, particularly if the disease is untreated for a long time. Elevated thyroid hormone can lead to irregularities in your heart rhythm. 

This can lead to a heart rhythm problem called atrial fibrillation (commonly called afib), in which the first chamber of the heart, the atria, doesn’t contract normally. If not treated, this can lead to blood clots and stroke.

Thyroid Storm

A small percentage of people with Graves' disease develop thyroid storm, a life-threatening syndrome that can happen when a large amount of thyroid hormone is suddenly released. It is usually brought on by some sort of trigger, like an infection.

People with thyroid storm can have even more exaggerated symptoms from hyperthyroidism as well as additional symptoms like fever, very low blood pressure, liver failure, altered mental status, and even heart failure. It is a medical emergency that requires immediate treatment. 

What Causes Graves' Disease?

Graves' disease is an autoimmune disease and researchers are still trying to figure out exactly what causes it. They know that something causes the immune system to overproduce the antibody thyroid-stimulating immunoglobulin (TSI). TSI attaches to your healthy thyroid cells, causing your thyroid to produce too many thyroid hormones. Excess thyroid hormones travel around the body, causing the disease’s symptoms.

Researchers are still trying to understand why this happens in some people but not in others. Some people have variations in certain genes that may play a role, but not everyone with these variants gets Graves' disease. We think certain environmental factors, like a virus, might help trigger the disease in susceptible people. 

Risk Factors

Women are roughly five times more likely to get Graves' disease, and female genetic sex at birth is the most well-established risk factor for the disease.

Other risk factors for developing Graves' disease aren’t completely clear, but they may include:

• Psychological stress
• Smoking
• Previous thyroid damage
• Vitamin D deficiency
• Personal or family history of other autoimmune disorder

Diagnosis

Your medical history and physical exam may make your healthcare provider suspicious that some sort of hyperthyroidism is the cause. 

It’s important for your medical provider to diagnose not just hyperthyroidism but the specific underlying cause of your hyperthyroidism, because Graves' disease isn't the only possibility. For example, some other potential causes include:

• Thyroid adenoma, or an overgrowth of thyroid tissue (mostly benign)
• Inflammation of the thyroid (thyroiditis), like from a viral infection

Tests for Hyperthyroidism

Important tests to demonstrate hyperthyroidism (not specifically Graves' disease) are:

• Thyroid stimulating hormone (TSH) blood test: This test measures the amount of TSH in your blood. This can tell you if thyroid is making the right level of thyroid hormones. Low levels of TSH may indicate hyperthyroidism.
• T3 (triiodothyronine) and T4 (thyroxine) blood tests: T3 and T4 are different versions of thyroid hormones. Elevated T3 and/or T4 levels are a sign of hyperthyroidism.

Tests for the Cause of Hyperthyroidism

Because the thyroid gland is the main part of the body that takes up iodine, radioactive iodine can be used to get more information about how the thyroid is functioning. So, an important diagnostic is a radioactive iodine uptake test followed by a thyroid imaging scan.

During the test, you need to swallow a pill with radioactive iodine. The iodine is absorbed by areas of your thyroid, making your thyroid more visible by defining its shape, size, and position. A technician traces the iodine in your body using a special camera that can take photos of your thyroid.

A thyroid ultrasound may also be used to help find the cause of hypothyroidism. This is an imaging alternative to a radioactive iodine uptake test that instead uses sound waves to develop a 2-dimensional image of your thyroid.

Treatments for Graves' Disease

Treatment for Graves' disease can be broken into immediate management versus long-term approaches.

Immediate Symptom Management

Your healthcare provider is likely to use a type of medication called a beta-blocker to help initially manage your symptoms. Beta-blockers are generally used to treat heart and circulatory conditions, slowing down cell activity responsible for overstimulation of these areas. They can help treat symptoms like a racing heartbeat, anxiety, and tremors. Inderal (propranolol) is one commonly used beta-blocker medication for Graves' disease.

Long-term Treatment

Three main long-term treatment options exist for Graves' disease. The best choice for you may vary based on your age, your overall health status, and your personal preferences. 

• Antithyroid medications: These block the synthesis of thyroid hormone. A drug called Tapazole (methimazole) is the first choice for most people. You might take it for the rest of your life, go into remission after 1 to 2 years of taking it, or you might use it until you decide on a different long-term approach. 
• Surgical removal of the thyroid gland: Surgery to remove the thyroid gland—called a thyroidectomy—is another option, but surgery always carries additional risks. It generally makes the most sense for people who can’t use other methods or people who have a goiter that might need to be removed.
• Destruction ("ablation") of the thyroid gland: Another option is taking oral radioactive iodine to destroy the thyroid gland. The radioactive iodine is taken up by your thyroid gland, where it kills thyroid cells but doesn’t have much effect on the rest of your body. 

Prevention

There is a lot we don’t understand about preventing Graves' disease. However, you may be able to reduce your risk by not smoking or by quitting smoking if you do already. Quitting may also decrease your risk of developing eye symptoms from Graves' disease, which sometimes happens even after radioactive iodine treatment.

Comorbid Conditions

Graves' disease also increases the risk of certain medical conditions, including: 

• Because of the impacts on bone turnover, people with untreated Graves' are at increased risk for osteoporosis and broken bones over the long term.
• Thyroid hormone can also affect your menstrual cycle. Particularly if untreated, Graves' disease may increase the risk of infertility.
• Having Graves' disease may also increase the risk of getting another disease caused by autoimmune problems, perhaps because of some similar underlying causes. For example, you might have a somewhat increased risk of vitiligo, rheumatoid arthritis, or type 1 diabetes.

Living With Graves' Disease

The outlook is good for people with treated Graves' disease, but the specifics may differ based on your treatment decisions.

Some people can take antithyroid medications for a while and then get off them without having symptoms of Graves' disease come back. In roughly half of people with Graves', these symptoms return within a year after tapering off their medication. It is critical to keep taking medications as prescribed. Abruptly stopping your antithyroid medication might lead to a life-threatening episode of thyroid storm.

Radioactive ablation of the thyroid is almost always successful at fixing hyperthyroidism, although it may take a repeated dose or two. Surgery to remove the whole gland also cures hyperthyroidism. However, if you have radioactive ablation or surgical removal of your thyroid, you will develop permanent hypothyroidism, low levels of thyroid hormone, because your thyroid gland is no longer working at all.

To prevent a different set of medical problems from that, you have to take supplementary thyroid hormone for the rest of your life. Although this is manageable, it is another reason some people opt to try antithyroid medication first.