Known as the most common cause of hyperthyroidism, Graves’ disease is a type of autoimmune disorder in which the immune system starts attacking the thyroid gland by creating thyroid-stimulating immunoglobulin (TSI), an antibody that protects against viruses and bacteria, but it attacks the thyroid gland causing it to make more thyroid hormone than the body needs.
Also called toxic diffuse goiter, this disease was named after Dr. Robert Graves, an Irish surgeon who described the condition in 1835.
Graves’ disease is primarily characterized by exophthalmos or the bulging of the eyes that affects up to 80% of patients diagnosed with the medical condition.
The exact cause of Graves’ disease still remains unclear, although a combination of environmental and genetic factors have been linked to the condition. In the United States, Graves’ disease affects 1 in every 200 people and it is more common in women.
With iodine deficiency disorders being a major global public health problem, the World Health Organization and United Nations Children’s Fund recommended universal salt iodization (USI) in more than 120 countries around the world.
In the United States, the Tolerable Upper Intake Level (UL) is 1,100 microgram per day for adults, but excess iodine intake has also become a problem in some populations.
Iodine-induced hyperthyroidism (IIH) is believed to be a side effect of excessive iodine supplementation known as “Jod-Basedow phenomenon” and it is more prevalent in populations that follow recent iodine fortification and in individuals with thyroid nodular changes.
Iodine is a key ingredient in producing T4 and T3, so any excess iodine in the body will result to an overproduction of these hormones.
In some cases, the thyroid gland could become inflamed causing cell damage and destruction that results to the leakage of thyroid hormones into the blood.
If left untreated, this will lead to hyperthyroidism and eventually to a condition called thyrotoxicosis.
Once the thyroid hormone leaks out of the thyroid gland, it could cause hyperthyroidism that lasts up to 3 months followed by hypothyroidism that lasts up to 18 months or even permanently in some patients.
There are three types of thyroiditis. Subacute thyroiditis is characterized by a painful and enlarged thyroid gland and it’s usually caused by an infection.
Postpartum thyroiditis occurs in women who gave birth. Then there’s silent thyroiditis where the patient doesn’t feel any pain or enlargement of the thyroid gland.
The exact cause of thyroiditis is still unknown, but studies reveal that the ability to make anti-thyroid antibodies tend to run in families.
Thyroiditis may also be caused by an infection that results to the inflammation of the thyroid gland. Drugs such as amiodarone and interferone have also been linked to thyroid cell damage leading to thyroiditis.
Benign thyroid nodules
A thyroid nodule is a lump that grows in the thyroid gland. Over time, the nodules can grow or multiply causing concerns of cancer.
Fortunately, only 5% of all thyroid nodules are malignant and the rest are colloid nodules, multi-nodular goiters, thyroid cysts or hyperfunctioning thyroid nodules. If left untreated, however, thyroid nodules could later cause hyperthyroidism.