Having a problem with one’s thyroid gland is, unfortunately, a far too familiar issue for many around the country. The American Thyroid Association estimates that some 20 million Americans have a thyroid disease and that 12% of all Americans will develop some form of thyroid condition at some point during their lifetime. Moreover, it is likely that as many as 60% of those with a condition don’t even know they have it.
The most common type of thyroid disease around the United States (and around the world) is called hyperthyroidism, a condition where the thyroid gland is overactive and therefore thyroid hormone levels are too high. The effects of this condition can be detrimental to overall health since many normal bodily functions, such as heart rate and metabolism, can be sped up to a devastating degree.
Since the symptoms of hyperthyroidism can run the gamut between no symptoms and numerous, severe symptoms, it can be hard to diagnose. This is also why a fair number of people are unaware they have the condition. But when a doctor is able to make a diagnosis, the question of cause more often than not comes back to the usual suspect: Graves’ disease.
How Does the Thyroid Function?
Before understanding how Graves’ disease can lead to hyperthyroidism, it’s important to understand the function of the thyroid gland. As one of the primary glands of the endocrine system, the thyroid gland acts a chemical messenger in the body; it produces and secretes three important hormones: thyroxine, triiodothyronine, and calcitonin.
These hormones, like all hormones, are molecules that the body uses as signals to regulate various body functions. Thyroxine and triiodothyronine, usually referred to as the “thyroid hormones,” are critically important because they have an effect on almost all the cells in the body. In addition to influencing heart rate and blood pressure, thyroid hormones regulate the metabolic rate and other activities that tell our cells how to derive energy from available materials in the bloodstream.
Overall, the hormones a normally functioning thyroid gland secretes work in concert with the rest of the endocrine system in order to regulate all body systems. When the quantity of any hormone is out of balance (either too much or too little), problems start to form. This is the core concern with hyperthyroidism and, by extension, Graves’ disease.
What is Graves’ Disease?
Named after Robert James Graves, an Irish doctor who was the first to describe it, Graves’ disease is an autoimmune disorder (any condition where your body’s immune system attacks a part of your body that it mistakes as foreign) that affects the thyroid gland. It is also sometimes referred to as toxic diffuse goiter due to the typical enlargement of the gland.
The defining characteristic of Graves’ disease is that your immune system produces unwelcome receptor antibodies that negatively affect the thyroid. An antibody is usually generated by the body in order to fight any foreign agents it detects. In Graves’ disease, these antibodies instead see the thyroid gland as a foreign agent and act accordingly.
Referred to as thyroid-stimulating immunoglobulins (TSI), these antibodies mimic the thyroid-stimulating hormone (TSH) produced by the pituitary gland. When everything is functioning normally, the pituitary gland secretes TSH which in turn triggers the thyroid to produce the thyroid hormones that regulate cell metabolism. With Graves’, however, the TSI antibodies bind to the thyroid gland’s receptors for TSH and lead to an overactive thyroid.
What Causes Graves’ Disease?
Though the mechanism for what happens in Graves’ is fairly well understood, the underlying cause is still something of a mystery. Doctors don’t really know why in some people the immune system begins to see the thyroid gland as a foreign body, nor why it stimulates the cells of the thyroid rather than attack as antibodies tend to do to foreign substances.
Some current research suggests a possible genetic predisposition for Graves’ related to the human leukocyte antigen, a group of genes that are involved with the immune system. Scientists have also speculated that because of its autoimmune nature, a viral or bacterial infectious trigger that inadvertently leads to the creation of the harmful antibodies.
What are the Symptoms of Graves’ Disease?
As Graves’ disease is the precursor to hyperthyroidism, its symptoms are very similar to the symptoms of hyperthyroidism. Some of those common symptoms shared by both conditions are as follows:
- Nervousness, anxiety, or irritability
- Rapid heartbeat
- Irregular heartbeat or palpitations
- Fatigue or muscle weakness
- Hand tremors
- Difficulty sleeping
- Diarrhea or irregular bowel movements
- Unexplained weight loss
- Sensitivity to heat and an increase in perspiration
- Menstrual cycle changes
- Loss of libido
There are additionally some symptoms that are exclusive to Graves’ disease. One of the most noticeable is Graves’ ophthalmopathy, a condition that is known primarily for causing bulging eyes (technically referred to as (exophthalmos). Graves’ ophthalmopathy is an eye disease that occurs because of the underlying immune system problems and related inflammation of the optic nerve, muscle, and other tissue around the eyeballs.
As the thyroid is instructed to produce more and more thyroid hormone, one of the common effects of this is an enlarged thyroid gland. When this happens, sometimes the thyroid grows so large that the swelling can be seen from outside the body. This swelling that can happen is called a goiter, and the presence of a goiter is also a very strong symptom of Graves’ disease.
Another symptom that is specific to Graves’ disease is reddening or thickening of the skin in certain parts of the body. This somewhat rare related condition is called Graves’ dermopathy (technically referred to as pretibial myxedema), and it typically affects the skin on the tops of your feet or your shins. The cause is suspected to be related to the build-up of carbohydrates in the skin.
Who is at Risk for Graves’ Disease?
Many aspects of Graves’ disease still eludes doctors and researchers, including predictions about who is most likely to get it. In general, though, women are up to eight times more likely to develop the condition than men, and it most often affects women who are between 30 and 60 years old. Beyond that, there are a few other factors that seem to indicate a higher risk:
- Having a history of infection: because of the way antibodies function in Graves’ disease, it’s possible that prior infections may increase your chances.
- Family members who have had Graves’ disease: the autoimmune nature of the disease suggests that there is a genetic component that doctors continue to research.
- Other autoimmune diseases: lupus, type 1 diabetes, rheumatoid arthritis, and pernicious anemia affect immune function and might play a role in Graves’.
- Recent pregnancy: the impact of a pregnancy on the thyroid gland could potentially be a trigger for some women.
- Stress or emotional trauma
- Smoking: in addition to its potential to put you at risk for Graves’ disease, smoking also appears to be a leading cause of Graves’ ophthalmopathy.
Diagnosis and Treatment
When a doctor suspects Graves’ disease, the condition can sometimes be diagnosed through a physical exam. To confirm the diagnosis, the doctor may order a blood test to determine the amount of thyroid hormone or antibodies in your blood. Because iodine is a crucial substance in the thyroid, another option is a radioactive iodine uptake test (RAIU).
If the condition is confirmed, there are a few different options available. Since there is no “cure” for Graves’ disease, most treatments involve finding some way to stop the thyroid gland from continuing to produce too much hormone. Antithyroid drugs like methimazole (MMI) or propylthiouracil (PTU) might be prescribed to chemically restrict the amount of hormone produced.
For cases where medication isn’t an option (such as during early pregnancy), there are two other approaches that involve forcing the thyroid to stop being overactive. One way is through radioiodine therapy, which uses ingested radioactive iodine to intentionally damage thyroid cells. Alternatively, thyroid surgery (thyroidectomy) involves removing part or all of the thyroid gland. In both of these treatment options, the patient will be required to take thyroid hormone supplements for the rest of their life.
Graves Disease Appointment
Graves’ disease, and subsequent hyperthyroidism, can be a devastating condition if left undiagnosed and untreated. If you think you might have some of the symptoms described here, contact The Woman’s Clinic today to make an appointment.