Thyroiditis

Thyroiditis is inflammation of the thyroid gland, which can cause neck pain, swelling, and changes in thyroid hormone levels. The condition ranges from self-limited forms to chronic autoimmune disease, and its presentation may include hyperthyroid, hypothyroid, or normal hormone levels at different times during the illness.

Common forms include Hashimoto's thyroiditis, an autoimmune destruction of the gland that usually leads to gradual hypothyroidism; subacute granulomatous thyroiditis (de Quervain's), often following a viral illness and typically presenting with a tender, enlarged thyroid; painless thyroiditis, including postpartum thyroiditis, which can cause transient thyrotoxicosis followed by hypothyroidism; and infectious thyroiditis, which is rare and generally requires antibiotics. Drug-induced thyroiditis can occur with medications such as amiodarone or immune therapies and may mimic other forms.

Symptoms depend on the phase and type. Patients may experience neck pain and swelling, fatigue, weight change, heat or cold intolerance, palpitations, and mood symptoms. The thyrotoxic phase shows symptoms of excess thyroid hormone, while the hypothyroid phase presents with low energy and cold intolerance.

Diagnosis relies on thyroid function tests (TSH and free T4), along with clinical history. Tests for autoimmune thyroid antibodies, inflammatory markers (ESR/CRP), and ultrasound of the thyroid are common; a radioactive iodine uptake scan helps distinguish active inflammatory thyroiditis from other conditions.

Treatment is type-specific. Autoimmune Hashimoto's disease is managed with thyroid hormone replacement if hypothyroidism is present. Painful subacute thyroiditis is treated with NSAIDs or steroids; beta-blockers may help during thyrotoxic symptoms. Antibiotics are used for bacterial thyroiditis, and most drug-induced or postpartum/silent forms are self-limited, with monitoring or temporary hormone therapy as needed. Prognosis varies by form, with many cases resolving or stabilizing, while autoimmune disease may require ongoing management.