The Key Types of Thyroiditis

doctor checking a woman's neck

The term thyroiditis refers to a number of disorders that involve inflammation of the thyroid gland. Thyroiditis commonly affects women more frequently than men, and may have few to no symptoms, or cause significant symptoms to sufferers.


According to the American Thyroid Association, "thyroiditis is caused by an attack on the thyroid, causing inflammation and damage to the thyroid cells. Antibodies that attack the thyroid cause most types of thyroiditis. No one knows why certain people make thyroid antibodies, although this tends to run in families. Thyroiditis can also be caused by an infection, such as a virus or bacteria, which works in the same way as antibodies to cause inflammation in the gland. Finally, drugs such as interferon and amiodarone, can also damage thyroid cells and cause thyroiditis." (American Thyroid Association: Thyroiditis Brochure.)


The symptoms of thyroiditis can be similar to hyperthyroidism — with anxiety, high heart rate, insomnia, weight loss, muscle weakness, and other signs of an overactive thyroid gland. The symptoms can also be similar to those of hypothyroidism, including fatigue, weight gain, hair loss, depression, memory problems, and other signs of an underactive or slowed-down thyroid gland.

Some forms of thyroiditis also include pain, tenderness, or soreness in the neck or throat area.

Hashimoto's Is the Most Common Type of Thyroiditis

Hashimoto's Thyroiditis is the most common type of thyroiditis in the United States. Hashimoto's is an autoimmune disease, and as part of the disease process, antithyroid antibodies are produced. These antibodies attack the thyroid gland, causing inflammation to the gland (known as goiter), the formation of thyroid nodules in some cases, and for some patients, Hashimoto's causes the destruction of the gland itself. Hashimoto's thyroiditis is the most common cause of hypothyroidism in the United States.

Other Types 

Subacute Granulomatous Thyroiditis / de Quervain's Thyroiditis is a painful type of thyroiditis, also known as subacute nonsuppurative thyroiditis, de Quervain's Thyroiditis, or painful subacute thyroiditis. The symptoms of subacute nonsuppurative thyroiditis typically include neck pain and tenderness. Some patients experience difficulty swallowing or even fever. The cause of this particular type of thyroiditis is thought to be a virus.

Acute Infectious Thyroiditis falls into the category of "painful" types of thyroiditis. Acute infectious thyroiditis is usually caused by a bacterial infection — often with staph or strep bacteria. The infection subsequently causes an abscess in the thyroid gland.

Painless Thyroiditis/Silent Thyroiditis is also frequently referred to as silent thyroiditis or subacute lymphocytic thyroiditis. It's thought that painless thyroiditis may be responsible for as much as 10 percent of hyperthyroidism, because the typical course of painless thyroiditis is a temporary period of overactivity — hyperthyroidism — which is then sometimes followed by a period of hypothyroidism, followed by a return to normal thyroid function. In painless thyroiditis, the thyroid gland usually does not become enlarged.

Riedel's Thyroiditis/Invasive Thyroiditis is in the category of "painless" types of thyroiditis. It is also known as Riedel's struma, fibrous thyroiditis, and invasive thyroiditis. In Riedel's thyroiditis, the normal thyroid tissue is replaced by what's known as fibrosis — excessive amounts of connective tissue. This fibrosis can also extend beyond the thyroid, reaching into other parts of the neck, and may cause the thyroid to become abnormally attached to the neck.

Postpartum Thyroiditis is a "painless" type of thyroiditis that initially occurs in the first year after childbirth, miscarriage, or induced abortion. It is sometimes considered a variation of autoimmune thyroiditis, also known as Hashimoto's thyroiditis. Postpartum thyroiditis may include both hyperthyroid and hypothyroid symptoms, sometimes in cycles. In some cases, the thyroid returns to normal function, but some patients with postpartum thyroiditis end up permanently hypothyroid, requiring lifelong treatment.


Treatment of thyroiditis depends on which type of thyroiditis is diagnosed, and the effects on the gland and patient symptoms.

In some cases, thyroid hormone replacement is used to treat resulting hypothyroidism. The treatment is often tapered off, to determine if the hypothyroidism is permanent and requires continued treatment.

Painful forms of thyroiditis are sometimes treated with non-steroidal anti-inflammatory medications, such as ibuprofen or aspirin. For severe or prolonged thyroiditis, steroid treatment is sometimes used.

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