(See also Overview of Thyroid Function Overview of Thyroid Function The thyroid gland, located in the anterior neck just below the cricoid cartilage, consists of 2 lobes connected by an isthmus. Follicular cells in the gland produce the 2 main thyroid hormones... read more .)
Hashimoto thyroiditis is believed to be the most common cause of primary hypothyroidism in North America. It is several times more prevalent among women. Incidence increases with age and in patients with chromosomal disorders, including Down syndrome Down Syndrome (Trisomy 21) Down syndrome is an anomaly of chromosome 21 that can cause intellectual disability, microcephaly, short stature, and characteristic facies. Diagnosis is suggested by physical anomalies and... read more , Turner syndrome Turner Syndrome In Turner syndrome, girls are born with one of their two X chromosomes partly or completely missing. Diagnosis is based on clinical findings and is confirmed by cytogenetic analysis. Treatment... read more , and Klinefelter syndrome Klinefelter Syndrome (47,XXY) Klinefelter syndrome is the presence of two or more X chromosomes plus one Y, resulting in a phenotypic male. Diagnosis is based on clinical findings and is confirmed by cytogenetic analysis... read more . A family history of thyroid disorders is common.
Hashimoto thyroiditis, like Graves disease Etiology Hyperthyroidism is characterized by hypermetabolism and elevated serum levels of free thyroid hormones. Symptoms are many and include tachycardia, fatigue, weight loss, nervousness, and tremor... read more , is sometimes associated with other autoimmune disorders, including Addison disease Addison Disease Addison disease is an insidious, usually progressive hypofunctioning of the adrenal cortex. It causes various symptoms, including hypotension and hyperpigmentation, and can lead to adrenal crisis... read more (adrenal insufficiency), type 1 diabetes mellitus Diabetes Mellitus (DM) Diabetes mellitus is impaired insulin secretion and variable degrees of peripheral insulin resistance leading to hyperglycemia. Early symptoms are related to hyperglycemia and include polydipsia... read more , hypoparathyroidism Hypoparathyroidism Hypocalcemia is a total serum calcium concentration 8.8 mg/dL ( 2.20 mmol/L) in the presence of normal plasma protein concentrations or a serum ionized calcium concentration 4.7 mg/dL ( 1.17... read more , vitiligo Vitiligo Vitiligo is a loss of skin melanocytes that causes areas of skin depigmentation of varying sizes. Cause is unknown, but genetic and autoimmune factors are likely. Diagnosis is usually clear... read more , premature graying of hair, pernicious anemia, connective tissue disorders (eg, rheumatoid arthritis Rheumatoid Arthritis (RA) Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease that primarily involves the joints. RA causes damage mediated by cytokines, chemokines, and metalloproteases. Characteristically... read more , systemic lupus erythematosus Systemic Lupus Erythematosus (SLE) Systemic lupus erythematosus is a chronic, multisystem, inflammatory disorder of autoimmune etiology, occurring predominantly in young women. Common manifestations may include arthralgias and... read more , Sjögren syndrome Sjögren Syndrome Sjögren syndrome is a relatively common chronic, autoimmune, systemic, inflammatory disorder of unknown cause. It is characterized by dryness of the mouth, eyes, and other mucous membranes due... read more ), celiac disease Celiac Disease Celiac disease is an immunologically mediated disease in genetically susceptible people caused by intolerance to gluten, resulting in mucosal inflammation and villous atrophy, which causes malabsorption... read more , and type 2 polyglandular deficiency syndrome Type 2 polyglandular deficiency Polyglandular deficiency syndromes (PDS) are characterized by sequential or simultaneous deficiencies in the function of several endocrine glands that have a common cause. Etiology is most often... read more (Schmidt syndrome—a combination of Addison disease with hypothyroidism secondary to Hashimoto thyroiditis and/or type 1 diabetes mellitus). There may be an increased incidence of thyroid tumors, rarely thyroid lymphoma. Pathologically, there is extensive infiltration of lymphocytes with lymphoid follicles and scarring.
Symptoms and Signs of Hashimoto Thyroiditis
Patients complain of painless enlargement of the thyroid or fullness in the throat. Examination reveals a nontender goiter that is smooth or nodular, firm, and more rubbery than the normal thyroid. Many patients present with symptoms of hypothyroidism Symptoms and Signs Hypothyroidism is thyroid hormone deficiency. It is diagnosed by clinical features such as a typical facial appearance, hoarse slow speech, and dry skin and by low levels of thyroid hormones... read more , but some present with hyperthyroidism Hyperthyroidism Hyperthyroidism is characterized by hypermetabolism and elevated serum levels of free thyroid hormones. Symptoms are many and include tachycardia, fatigue, weight loss, nervousness, and tremor... read more that may be due to thyroiditis.
Diagnosis of Hashimoto Thyroiditis
Thyroid-stimulating hormone (TSH)
Testing Laboratory Testing of Thyroid Function The thyroid gland, located in the anterior neck just below the cricoid cartilage, consists of 2 lobes connected by an isthmus. Follicular cells in the gland produce the 2 main thyroid hormones... read more consists of measuring T4, TSH, and thyroid autoantibodies. Early in the disease, T4 and TSH levels are normal and there are high levels of thyroid peroxidase antibodies and, less commonly, of antithyroglobulin antibodies.
Thyroid ultrasonography should be done if there are palpable nodules. Ultrasonography often reveals that the thyroid tissue has a heterogeneous, hypoechoic echotexture with septations that form hypoechoic micronodules.
Testing for other autoimmune disorders is warranted only when clinical manifestations are present.
Treatment of Hashimoto Thyroiditis
Thyroid hormone replacement
Occasionally, hypothyroidism is transient, but most patients require lifelong thyroid hormone replacement, typically L-thyroxine (levothyroxine) 75 to 150 mcg orally once a day.
Hashimoto thyroiditis is autoimmune inflammation of the thyroid.
Patients sometimes have other autoimmune disorders.
Thyroxine (T4) and thyroid-stimulating hormone (TSH) levels initially are normal, but later, T4 declines and TSH rises, and most patients become clinically hypothyroid.
There are high levels of thyroid peroxidase antibodies and, less commonly, of antithyroglobulin antibodies.
Lifelong thyroid hormone replacement is typically needed.