Autoimmune Thyroiditis (Hashimoto's): What Kind of Disease Is It

If the conclusion states "autoimmune thyroiditis" or "Hashimoto's thyroiditis," this refers to chronic autoimmune inflammation of the thyroid gland. The disease develops slowly and does not always result in persistent loss of function. Below is what this condition is and how it is confirmed.

What Autoimmune Thyroiditis and Hashimoto's Disease Are

AIT (Hashimoto's thyroiditis, chronic autoimmune thyroiditis, lymphocytic thyroiditis, lymphomatous goiter) is chronic inflammation of the thyroid gland of autoimmune origin. Due to prolonged lymphoid infiltration, the gland tissue is gradually destroyed, and the outcome may be primary hypothyroidism. The disease was first described by the Japanese surgeon Hakaru Hashimoto in 1912.

In the hypertrophic variant, the gland is diffusely firm, and function is preserved or moderately reduced; in the atrophic form, the gland is small and hypothyroidism is present. AIT is found in 3–4% of the world's population, clinically manifest forms in about 1%, and there are 4–8 times more women among patients than men.

What to remember: this is long-term autoimmune inflammation, not a one-time episode; gland function does not decline in everyone.

Is It Cancer? Why AIT Is Not a Tumor

No. AIT is inflammation in which the immune system reacts against the gland's own cells, not a malignant growth of tissue. Rarely, cancer or lymphoma of the thyroid gland develops with this condition, so AIT is differentiated from nodular goiter, thyroid cancer, and other chronic thyroiditides.

What to remember: a diagnosis of AIT does not mean a tumor; mention of cancer refers to rare exceptions and to differential diagnosis.

Why Autoimmune Damage to the Thyroid Gland Develops

The basis is a genetically determined defect in the immune response: T lymphocytes attack the body's own thyrocytes and destroy them, and antibodies to the thyroid gland are found in the blood of most patients. In 50% of relatives of such patients, circulating antibodies are also present. AIT is often associated with pernicious anemia, type 1 diabetes mellitus, and vitiligo.

Triggering factors include pregnancy and childbirth, iodine deficiency or excess, deterioration of the environmental situation, radioactive contamination, infectious and inflammatory processes, and less commonly trauma or surgery on the gland.

What to remember: the basis is a failure of immune regulation, while heredity and external factors only increase the likelihood of the disease.

Symptoms and the Connection with Goiter and Hypothyroidism

In the euthyroid phase and in the phase of subclinical hypothyroidism, there are usually no complaints. Less often, enlargement of the gland—goiter—comes to the fore, which rarely reaches significant degrees. When hypothyroidism develops, its signs increase.

These are fatigue, cold intolerance, weight gain, constipation, difficulty concentrating, dry skin, hair loss, and a hoarse voice. Symptoms develop slowly; neck enlargement is sometimes the only early manifestation, and at a late stage the gland is small or shrunken.

The course is usually stable for years. Untreated hypothyroidism increases the risk of heart and bone problems, including osteoporosis.

What to remember: AIT itself is often asymptomatic, complaints appear when function declines, and goiter is sometimes the first visible sign.

How AIT Is Diagnosed

The doctor clarifies complaints, family history of thyroid and autoimmune diseases, recent pregnancy, and examines the neck. Laboratory evaluation includes free T4, TSH, and thyroid autoantibodies. Imaging studies and fine-needle biopsy are usually not needed to diagnose Hashimoto's thyroiditis.

What to remember: the key tests are TSH, free T4, and thyroid antibodies; biopsy is not required in typical cases.

Which Doctor to See and When Not to Delay the Visit

Start with a general practitioner, who will refer to an endocrinologist if necessary. No specific therapy for AIT has been developed; in confirmed hypothyroidism, the doctor decides on replacement therapy and monitors TSH. If function is preserved, observation is often sufficient.

There is no prevention of AIT. During pregnancy with hypothyroidism, additional examinations are needed: without treatment, it increases the risk of preeclampsia, developmental defects, preterm birth, and miscarriage.

Reasons to see a doctor:

• neck enlargement or a sensation of goiter;
• fatigue, cold intolerance, weight gain, constipation without a clear cause;
• dry skin, hair loss, hoarse voice, irregular menstruation;
• thyroid diseases or other autoimmune diseases in relatives.

The diagnosis of AIT itself is not a reason to call an ambulance. Numbers 103 and 112 are needed for altered consciousness up to coma against the background of severe untreated hypothyroidism: such a condition is treated in hospital.

This material is for reference and does not replace a doctor's consultation: the decision on examination and observation remains with the doctor.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer