Thyroid diseases are so common around the world that some people are not even aware that they have it because they don’t feel any symptoms. According to the American Thyroid Association (ATA), at least 20 million Americans have a form of thyroid disease with up to 60% of them unaware of their condition.
There are two common types of thyroid disease: hypothyroidism that affects 4.6% or 5 in every 100 people in the United States and hyperthyroidism that only affects 1 out of 100 Americans.
But while hyperthyroidism is not as common as hypothyroidism, it still deserves prompt medical attention, especially since complications can be devastating and patients may suffer for the rest of their lives if they don’t seek treatment right away.
An introduction to the thyroid gland
The thyroid gland is a butterfly-shaped organ located in the anterior aspect of the trachea on the lower neck. It consists of two lobes connected through the thyroid isthmus and its blood supply comes from the thyroid artery, which branches from the thyrocervical trunk.
The thyroid gland is primarily responsible for the production and secretion of thyroid hormones thyroxine (T4) and triiodothyronine (T3). Both of these hormones play an important role in cellular processes.
When the thyroid gland fails to function properly, it either under produces or over produces thyroid hormones that disrupt the balance in the body’s processes.
Hypothyroidism is a medical condition where the thyroid gland fails to produce enough thyroid hormones that the body needs, which in turn affects metabolism. People with hyperthyroidism usually have slow metabolism causing them to feel tired easily, become forgetful, become more sensitive to cool temperatures and even experience depression. Hashimoto’s thyroiditis is the most common cause of hypothyroidism.
Hyperthyroidism, on the other hand, results from an overactive thyroid that produces more hormones than the body requires. Patients with hyperthyroidism have fast metabolism that leads to nervousness, muscle fatigue, rapid heart rate, diarrhea, sudden weight loss, goiter and difficulty sleeping.
Although less common, hyperthyroidism can cause serious health problems with the bones, heart, muscles and even fertility. Graves’ disease is the most common cause of hyperthyroidism.
Understanding Graves’ disease
Graves’ disease is a type of autoimmune disorder that affects the thyroid gland and eventually other organs including the skin and eyes. It accounts for up to 80% of hyperthyroidism cases, making it the most common cause of the thyroid disorder.
In the United States, hyperthyroidism has a prevalence rate of 1.2% and it occurs more in women who are between 20 and 50 years old. Graves’ disease was named after Dr. Robert Graves, an Irish physician who first described this type of hyperthyroidism.
The pathophysiology
The body is equipped with its own immune system that fights against bacteria and viruses. But in the case of Graves’ disease, the body’s immune system attacks the thyroid gland causing it to produce more thyroid hormone than the body needs.
Grave’s disease is primarily caused by the thyroid stimulating immunoglobulin (TSI) that’s synthesized by B lymphocytes. The disease process begins with the B lymphocytes being stimulated by T lymphocytes that are also sensitized by an antigen in the thyroid gland.
The resulting thyroid stimulating immunoglobulin then binds with the thyroid-stimulating hormone receptor (TSH), which triggers the action of the TSH. This process results in the stimulation of both the growth of the thyroid gland and the synthesis of the thyroid hormone causing hyperthyroidism.