Hyperthyroidism and Graves' Disease FAQ

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Here are some of the frequently asked questions about hyperthyroidism – an overactive thyroid.

What Is Hyperthyroidism?

Hyperthyroidism is an overfunctioning of the thyroid gland. This overfunctioning results in the production of too much thyroid hormone. Because thyroid hormone controls many bodily functions, this increase in the thyroid hormone level causes these bodily functions, such as heart rate, to speed up, resulting in hyperthyroid symptoms such as weight loss, anxiety, diarrhea, insomnia, and other symptoms of an overactive thyroid.


Are Hyperthyroidism and Graves' Disease the Same Thing? What's the Difference?

Graves' disease is the most common cause of hyperthyroidism. In Graves' disease, an autoimmune condition causes the thyroid gland to become overactive. Hyperthyroidism is the condition of overactivity. Not only Graves' disease, but Hashimoto's disease, hormonal changes in pregnancy, toxic nodules, some medications, and short-term inflammatory conditions like thyroiditis, can be the cause of hyperthyroidism. 

I've Heard Graves' Disease Described as an Autoimmune Disorder. What Does That Mean?

It means that the disease is caused by a malfunctioning of the immune system. This system is designed to protect us from such pathogens, such as viruses and bacteria. As part of the process, the immune system works by producing antibodies (also known as immunoglobulins or lymphocytes) to attack those viruses and bacteria. In some cases, this defense system gets confused and starts attacking our own otherwise healthy tissues, glands, organs and cells.

In Graves' disease, antibodies are produced that attack some of the proteins on the surface of thyroid cells. In response, the thyroid cells produce too much thyroid hormone, which, in turn, overstimulates the thyroid and causes hyperthyroidism.

How Can I Recognize Graves' Disease?

Even if you have Graves' disease, for some, it can take weeks, or even months, before you suspect you are sick because the symptoms may build gradually.

You may think you are just experiencing stress, or feeling extra anxious. Or the disease may actually make you happy in the short term, as one of the side effects of speeding up the thyroid can be weight loss and short-term energy. However, in the longer term, less desirable symptoms, such as muscle weakness, insomnia and tremor can also result. 

How Are Graves' Disease and Hyperthyroidism Tested and Diagnosed?

Testing for hyperthyroidism involves tests for TSH (which will be low), T4 or Free T4 (which will typically be high), and T3 or Free T3 (which will typically be high). To determine if Graves' disease is the cause, the Thyroid Stimulating Immunglobulin (TSI) antibodies will usually be tested. In addition, imaging tests – such as ultrasound, or a radioactive uptake scan – may be performed to identify changes to the gland to point to Graves' disease.

Can Excessive Thyroid Medication Given to Hypothyroid Sufferers Cause Hyperthyroidism?

Finding the proper dose of medications for hypothyroidism (an underfunctioning thyroid) is not an exact science. In fact, the dosages prescribed may sometimes be so strong that they cause hyperthyroidism as a result of overmedication. In such a case, your doctor should reduce the dosage of your medication until you are no longer symptomatically hyperthyroid and test results normalize.

If I Ignore My Hyperthyroidism, Will It Go Away?

For most forms of hyperthyroid disease, no, they will not go away. Not treating most forms of hyperthyroid can be very dangerous. Initially it can lead to an irregular heat beat, high blood pressure, and even a risk of heart attack or stroke, as part of a life-threatening complication called a thyroid storm.

In some cases, patients will go into remission due to antithyroid drug treatment, or immune system changes. The majority of Graves' and hyperthyroidism patients do require lifelong antithyroid drug treatment, or permanent treatments such as radioactive iodine (RA) or surgery that disable the thyroid and its ability to overproduce hormone.