Thyroiditis refers to inflammation of the thyroid gland. It encompasses a group of conditions with different causes, clinical courses, and treatments — but all share thyroid inflammation as a central feature. Thyroiditis can cause hyperthyroidism, hypothyroidism, or both at different phases.

Types of Thyroiditis

  • Hashimoto's Thyroiditis (Chronic Autoimmune Thyroiditis) — The most common form; an autoimmune attack leading to gradual hypothyroidism. Discussed in detail on its own page.
  • Subacute (De Quervain's) Thyroiditis — Painful thyroid inflammation, usually following a viral illness. Often causes transient hyperthyroidism followed by hypothyroidism, then recovery.
  • Postpartum Thyroiditis — Occurs in 5–9% of women within 1 year after delivery. Often follows the same pattern as subacute thyroiditis.
  • Silent (Painless) Thyroiditis — Similar clinical course to subacute thyroiditis but without neck pain; often autoimmune.
  • Drug-Induced Thyroiditis — Caused by medications including amiodarone, interferons, checkpoint inhibitor immunotherapy, and lithium.
  • Acute (Suppurative) Thyroiditis — Rare bacterial infection of the thyroid; presents with acute neck pain, fever, and tenderness.
  • Riedel's Thyroiditis — Very rare; fibrous tissue replaces normal thyroid tissue, causing a rock-hard, fixed goiter.

Subacute Thyroiditis — A Closer Look

Subacute thyroiditis typically follows a URI or flu-like illness by 2–6 weeks. The hallmark is a tender, painful thyroid gland. The clinical course has distinct phases:

  1. Thyrotoxic phase (2–8 weeks): Inflammation releases stored thyroid hormone — symptoms of hyperthyroidism plus neck pain
  2. Hypothyroid phase (weeks to months): Depleted hormone stores cause transient hypothyroidism
  3. Recovery phase: Most patients recover normal function within 12 months; ~5% develop permanent hypothyroidism

💊 Treatment of Subacute Thyroiditis: Anti-inflammatory medication (NSAIDs or, for severe cases, prednisone) treats the pain and inflammation. Beta-blockers manage hyperthyroid symptoms during the thyrotoxic phase. Antithyroid drugs are NOT used because the excess hormone comes from inflammation, not overproduction.

Key Takeaways

  • Thyroiditis is a group of conditions causing thyroid inflammation
  • Many forms cause a temporary pattern of hyperthyroidism followed by hypothyroidism
  • Subacute thyroiditis typically follows a viral illness and presents with a painful thyroid
  • Most forms of thyroiditis are self-limiting, but monitoring for permanent hypothyroidism is important
Medical Disclaimer: This article is for educational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider before making any changes to your treatment plan. Individual medical decisions should be made in partnership with your physician based on your specific circumstances.