Chronic thyroiditis (Hashimoto’s disease)

Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the pace of chemical activity in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).

Also known as: Hashimoto's thyroiditis, Chronic lymphocytic thyroiditis or Autoimmune thyroiditis

Definition

Chronic thyroiditis is swelling (inflammation) of the thyroid gland that often results in reduced thyroid function (hypothyroidism).

Causes, incidence, and risk factors

Chronic thyroiditis or Hashimoto's disease is a common thyroid gland disorder. It can occur at any age, but is most often seen in middle-aged women. It is caused by a reaction of the immune system against the thyroid gland.

The disease begins slowly. It may take months or even years for the condition to be detected. Chronic thyroiditis is most common in women and people with a family history of thyroid disease. It affects between 0.1% and 5% of all adults in Western countries.

Hashimoto's disease may, in rare cases, be associated with other endocrine disorders caused by the immune system. Hashimoto's disease can occur with adrenal insufficiency and type 1 diabetes. In these cases, the condition is called type 2 polyglandular autoimmune syndrome (PGA II).

Less commonly, Hashimoto's disease occurs as part of a condition called type 1 polyglandular autoimmune syndrome (PGA I), along with:

Adrenal insufficiency
Fungal infections of the mouth and nails
Hypoparathyroidism

Symptoms

Constipation
Difficulty concentrating or thinking
Dry skin
Enlarged neck or presence of goiter
Fatigue
Hair loss
Heavy and irregular periods
Intolerance to cold
Mild weight gain
Small or shrunken thyroid gland (late in the disease)

Other symptoms that can occur with this disease:

Note: There may be no symptoms.

Signs and tests

Laboratory tests to determine thyroid function include:

Free T4 test (low)
Serum TSH (high)
T3 (low or normal)
Thyroid autoantibodies:
- Antithyroid peroxidase antibody
- Antithyroglobulin antibody

Imaging studies are generally not needed to diagnose Hashimoto's thyroiditis.

This disease may also change the results of the following tests:

Complete blood count
Radioactive iodine uptake
Serum prolactin
Serum sodium
Total cholesterol

Treatment

A lack of thyroid hormone may develop. You may receive thyroid hormone replacement therapy (levothyroxine) if your body is not producing enough of the hormone. Or, you may receive it if you have signs of mild thyroid failure (such as elevated TSH). This condition is also known as subclinical hypothyroidism.

If there is no evidence of thyroid hormone deficiency, you may just need regular observation by a health care provider.

Expectations (prognosis)

The outcome is usually very good. The disease stays stable for years. If it does slowly progress to thyroid hormone deficiency (hypothyroidism), it can be treated with thyroid replacement therapy.

Complications

This condition can occur with other autoimmune disorders. In rare cases, thyroid cancer may develop.

Calling your health care provider

Call your health care provider if you develop symptoms of chronic thyroiditis.

Prevention

There is no known way to prevent this disorder. Being aware of risk factors may allow earlier diagnosis and treatment.

References

Ladenson P, Kim M. Thyroid. In: Goldman L and Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders; 2007:chap 244.

Brent GA, Larsen PR, Davies TF. Hypothyroidism and thyroiditis. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR, eds. Williams Textbook of Endocrinology. 11th ed. Philadelphia, Pa: Saunders Elsevier; 2008:chap 12.

Review date:: April 19, 2010
Reviewed by:: Ari S. Eckman, MD, Division of Endocrinology and Metabolism, Johns Hopkins School of Medicine, Baltimore, MD. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2008 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.