Hashimoto's thyroiditis

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at June 26, 2016
StartHashimoto's thyroiditis

Hashimoto's thyroiditis (also sometimes called Hashimoto's disease, Hashimoto disease, chronic thyroiditis or chronic lymphocytic thyroiditis) is a condition involving the thyroid gland. It is estimated that 14 million or more people are currently affected by this disease in the United States.

Contents

Definition & Facts

Hashimoto's thyroiditis was first discovered in 1912 by the Japanese physician by the same name. It is classified as an autoimmune disease because the body's own immune system begins to attack the thyroid gland. 

The thyroid gland is a small but essential gland that sits just below the voice box (larynx) in the throat (pharynx). It is only two inches long (or about five centimeters long), but it produces critical hormones that regulate heart rate, functions of the central nervous system, metabolism and weight, breathing, temperature and other important functions. As Hashimoto's thyroiditis develops, it causes hypothyroidism (deficiency of thyroid hormone). As the body's supply of essential hormones lessens, symptoms worsen.

Symptoms & Complaints 

For many people, the initial signs of Hashimoto's thyroiditis are so mild they are easily missed. However, as the thyroid continues to be affected by attacks from the body's own immune system, it will produce less and less of the hormones required to maintain regular function and the symptoms will worsen. The most commonly reported symptoms of Hashimoto's thyroiditis include:

Causes

To date, researchers have narrowed down the possible causes of Hashimoto's thyroiditis to a number of factors. However, the exact causes of this disease are still not fully known. Factors thought to influence the onset of Hashimoto's thyroiditis include:

  • Heredity. When an individual gets diagnosed with Hashimoto's thyroiditis, a medical history often reveals that there are family members who also have this disease or other autoimmune diseases. 
  • Radiation exposure. When an individual has been exposed to radiation, whether from working with nuclear material or as a result of receiving radiation treatment, that individual is more likely to develop a case of Hashimoto's thyroiditis in the future.
  • Ingestion of too much iodine. Iodine is required by the body as a dietary element, since the body needs small amounts of iodine to trigger production of thyroid hormones. But some drugs as well as certain forms of common table salt also contain iodine. When an individual ingests too much iodine, it may contribute to the onset of Hashimoto's thyroiditis.
  • Hormonal imbalances. Hashimoto's disease affects seven women for every one man who has the disease. Hormones involved in reproduction may play a role in the onset of the disease, especially in women who have a medical history of thyroid function disruption during pregnancy.

Diagnosis & Tests

Diagnosing Hashimoto's thyroiditis begins with taking a thorough individual and family medical history. This attempts to discover any past personal or family history of thyroid imbalance, surgery, or autoimmune diseases. From here, physicians can do a number of diagnostic tests to narrow down the diagnosis to Hashimoto's thyroiditis. Thyroid function tests may be conducted which include:

  • Thyroid-stimulating hormone levels test (TSH) test. This test is used to diagnose unusually high levels of thyroid-stimulating hormone or TSH in the body. TSH is produced by the pituitary gland, which regulates thyroid function. When TSH levels go up, it is usually a sign that the thyroid is not producing enough hormones on its own for proper bodily functioning.
  • T4 (thyroxine) test. T4 is a hormone produced by the thyroid gland. T3 (triiodothyronine), an active hormone used to regulate various body functions is produced from T4. When T4 levels are reduced, it can be a sign that the individual has Hashimoto's thyroiditis.
  • Antithyroid antibody test. These antibodies are only present if the individual's hypothyroidism is caused by the onset of Hashimoto's thyroiditis. 

In addition, imaging studies may be done during the diagnostic process. They could include:

  • Ultrasound. Ultrasound technology is used to detect the size, shape and texture of the thyroid gland. The ultrasound test will also look for thyroid nodes or growths (including malignant tumors) on the thyroid (thyroid cancer).
  • CT (computed tomography) scan. If the individual has developed a goiter (enlarged thyroid gland) as a result of Hashimoto's thyroiditis, a CT scan can be used to see how the goiter is affecting other nearby organs.

Treatment & Therapy

Once a doctor has definitively diagnosed Hashimoto's thyroiditis, treatment can begin in earnest. The type of recommended treatment depends in large part on how advanced the disease has become. Here are some of the most commonly recommended treatment options:

  • Wait and see (watchful waiting). If the case of Hashimoto's thyroiditis is very mild and symptoms are absent or few, it may be recommended to simply watch and wait. 
  • Hormone replacement therapy. If diagnostic tests show insufficient hormone production, a replacement therapy regime may be recommended. A synthetic form of thyroxine, levothyroxine can be taken orally.
  • Alternative therapies. For individuals who must eat a diet high in fiber, take calcium supplements, or medications to treat high cholesterol or ulcer, these may interfere with proper absorption of levothyroxine. In these cases, changing prescriptions, pursuing alternative remedies, or changing one's diet may be suggested.

Prevention & Prophylaxis

While researchers have not yet uncovered a way to completely prevent the onset of Hashimoto's thyroiditis, this is one of the most treatable diseases, and treatment is usually very successful.

An earlier diagnosis can greatly minimize discomfort from Hashimoto's symptoms. In some cases, simply by avoiding exposure to radiation or excessive amounts of iodine, it may be possible for certain individuals to prevent the onset of Hashimoto's thyroiditis.