Autoimmune disease occurs when the body’s immune system attacks its own tissues, mistakenly sensing them as foreign. When the body attacks thyroid gland tissue, it is known as Hashimoto’s thyroiditis, named after Japanese physician Dr. Haruko Hashimoto, who first described the illness in 1912. The condition is also called chronic lymphocytic thyroiditis or autoimmune thyroiditis.
Hashimoto’s thyroiditis is the most common cause of hypothyroidism in most of the world. It is also the most common autoimmune disease known to man. It affects males and females as well as the young and the old. But it is most common in women, is more likely to occur with age, and is more prevalent in those with a family history of thyroid disease or other autoimmune disease.
Hashimoto’s thyroiditis and hypothyroidism
The thyroid gland is part of the endocrine system. It regulates a wide range of vital body functions, influencing the rate at which every cell, tissue, and organ in your body — from your muscles, bones, and skin to your digestive tract, brain, and heart — functions. It does this primarily by secreting hormones that control how fast and efficiently cells convert nutrients into energy — a chemical activity known as metabolism.
Your doctor may suspect Hashimoto’s thyroiditis if you have low thyroid hormone levels, an enlarged thyroid gland (goiter), or, in some cases, repeated miscarriages without explanation. The diagnosis is usually confirmed with blood tests looking for specific antibodies to the thyroid.
Over time, Hashimoto’s thyroiditis can cause damage to the thyroid gland that results in hypothyroidism (insufficient thyroid hormone to meet the body’s needs). Hypothyroidism can cause a range of symptoms related to a slowed metabolism. Symptoms include fatigue, cold intolerance, loss of appetite, weight gain, depression, dry skin, hair loss, constipation, heavier menstrual periods, and high cholesterol.
Hypothyroidism isn’t the only complication associated with Hashimoto’s thyroiditis. In some, the condition can cause a goiter. The larger the goiter, the more likely it is to be visible. A goiter, particularly a large one, may also cause symptoms such as difficulty swallowing. When this occurs, surgery may be necessary to remove all or part of the goiter.
Standard treatment of Hashimoto’s thyroiditis
Once diagnosed, Hashimoto’s thyroiditis is typically treated with observation alone. In the event that hypothyroidism develops (even mild cases in the event of pregnancy), it is treated with thyroid medication (synthetic thyroid hormone).
Study explores a possible role for surgery
In 2019, a well-designed, provocative study done in Norway’s Telemark Hospital compared the benefits of thyroidectomy (removal of the thyroid) in patients with Hashimoto’s thyroiditis to thyroid medication alone.
Study participants were between 18 and 79 years old, had thyroid antibody levels that were at least 10 or more times greater than the upper limit of normal, and were being treated with thyroid medication. Despite having normal thyroid hormone levels (likely due to taking thyroid medication), study participants reported symptoms that interfered with measures of their quality of life including fatigue, the ability to function physically and socially, vitality, emotional and mental health, and bodily pain.
Of the 147 enrollees who completed the 18-month study, 73 underwent surgery. Those who did not have surgery continued to be treated with medication alone.
The results in those who had surgery were striking. Antibody levels fell to nearly normal. Quality of life improved. Fatigue improved to the point that it was comparable to the normal Norwegian population.
Cautious optimism, but more research is needed
This study raises the possibility of a role for surgery for patients with Hashimoto’s thyroiditis who continue to feel poorly despite optimal treatment with thyroid hormone.
However, the study, while well done, is a relatively small one. We need longer-term follow up and confirmation with additional studies done on diverse populations.
It’s also important to consider that thyroid surgery in patients with advanced Hashimoto’s thyroiditis is difficult. Rates of complications, including injury to the laryngeal nerve (which controls voice) and the parathyroid glands (which maintain normal blood calcium levels), are increased. What’s more, once the thyroid is removed, the body will no longer be able to make thyroid hormone, and the patient will have to take thyroid medication for the rest of their lives.
Thus, until further confirmatory studies are done, surgery for patients with Hashimoto’s thyroiditis should only be considered when thyroid enlargement is causing symptoms such as difficulty swallowing.