Thyroiditis & Goitre

Meet the patient

Two women sit in your endocrine clinic on the same morning, and they look alike — until you touch the neck. ^[1][2]

Patient A is a 34-year-old, eight weeks after a flu-like illness, now with a painful anterior neck she cannot bear to have her collar touch, pain shooting to her jaw and ear, low-grade fever, palpitations and a tremor. Her TSH is suppressed, her free T4 is high, and her ESR is 68 mm per hour. This is subacute (de Quervain) thyroiditis — the painful thyroiditis, post-viral, self-limiting, low radioactive iodine uptake, treated with NSAIDs or a short course of prednisolone and a beta-blocker for the thyrotoxic phase. ^[1][10]

Patient B is a 29-year-old, four months postpartum, with palpitations and weight loss for two weeks followed by crushing fatigue, dry skin and low mood that everyone — including her — has blamed on the baby. Her thyroid is painless and slightly firm, her TSH is suppressed then rises, her anti-TPO is positive. This is postpartum thyroiditis — painless, transient, anti-TPO-positive, and easily missed because the symptoms masquerade as new-mother exhaustion. ^[6]

Hold these two side by side and the whole topic slots into place. The exam question they pose is the one this page exists to answer: is this thyrotoxicosis a leak or a fire — and why does the answer change everything I prescribe? ^[1]

Leak or fire? — the one test that splits thyrotoxicosis

Low radioactive iodine uptake means the gland is leaking, not making; high uptake means it is overproducing. That single distinction resolves almost every thyrotoxicosis MCQ and SAQ, because the two arms are treated in opposite ways. ^[1][2]

In all the destructive thyroiditides, inflammation ruptures follicles and dumps preformed T4 and T3 into the circulation. The gland is not synthesising anything — the same inflammation has shut synthesis down — so it does not trap iodine, and the radioactive iodine uptake (RAIU) is low. In Graves disease the TSH-receptor antibody drives the gland to actively synthesise, so uptake is high and diffuse; in toxic multinodular goitre and toxic adenoma autonomous nodules make excess hormone, so uptake is high and focal or patchy. ^[1][2]

This is the face-off that earns marks: ^[1]

^[1]

The classic trap: every registrar reaches for carbimazole the moment the TSH comes back suppressed. In a destructive thyroiditis there is no synthesis to block — the hormone is already out of the gland and circulating — so antithyroid drugs do nothing useful and add needless risk. Beta-blocker for symptoms; let the leak resolve. ^[1]

Everyone forgets: the amiodarone patient breaks this rule. The huge iodine load suppresses uptake in both type 1 and type 2, so RAIU cannot tell them apart there — reach for colour-flow Doppler (vascular in type 1, flat in type 2) and interleukin-6 instead. ^[7]

Etymology for viva gold: Jod-Basedow is German Jod (iodine) plus Karl von Basedow, the German physician who described what the English-speaking world calls Graves and the French call Basedow — one disease, three national claimants. Wolff-Chaikoff is simply the two investigators who, in 1948, showed that a big iodine load transiently shuts down hormone synthesis — the gland's protective flinch before it escapes. ^[7]

The mantra for the whole topic: low uptake, beta-blocker; high uptake, antithyroid. Say it before you reach for the prescription, every single time. ^[1]

Three thyroiditides that look alike — name the discriminator

Three goitres walk into your clinic; one discriminator each tells them apart. Combine the bedside feel, the antibody pattern and the inflammatory markers and the diagnosis resolves before the scan returns. ^[1][6][10]

This is the four-way table examiners love, with the discriminating line beneath each name: ^[1]

^{[3] [23] [13] [14] [7] [11]}

The one-line discriminator each: Hashimoto — painless, anti-TPO, lifelong hypothyroid, possible malignant transformation; Subacute — painful, elevated ESR, post-viral, self-limiting; Postpartum or silent — painless, anti-TPO, transient, recurs in about three quarters; Amiodarone — check the drug chart, two types, managed differently. ^{[3][23][13][11]}

Enlarge

Hashimoto — the commonest one, and the one you treat for life

Hashimoto is organ-specific autoimmunity: anti-TPO, a firm rubbery goitre, and a slow slide into permanent hypothyroidism. It is the commonest cause of hypothyroidism and of goitre in iodine-sufficient regions, the form you will see every week of your career, and the reason most of your levothyroxine prescriptions exist. ^[3][5]

The histology is the story: CD8-positive T-cell-driven lymphocytic infiltration with germinal centres, Hurthle (oxyphil) cell metaplasia and fibrosis, with anti-thyroid peroxidase and anti-thyroglobulin antibodies fixing complement and driving antibody-dependent cytotoxicity. Early, the gland is firm, rubbery, goitrous and lobulated (infiltrated and hyperplastic under TSH drive); late, it is atrophic as fibrosis wins. Anti-TPO is positive in over 90 percent and predicts both onset and progression to permanent failure. ^[3][4]

The presentation is a painless, firm, diffusely enlarged goitre — often with a pyramidal lobe and a coarse lobulated surface — and gradual hypothyroidism: fatigue, cold intolerance, weight gain, constipation, dry skin, bradycardia, delayed reflexes, menorrhagia, and in severe disease periorbital puffiness and a serous effusion. It predominates in women 5 to 10 times, peaks between 30 and 50 years, clusters with other autoimmunity (type 1 diabetes, coeliac disease, pernicious anaemia, vitiligo, Addison disease), and links to HLA-DR3 and DR5 and Down and Turner syndromes; excess iodine intake can trigger it in susceptible people. ^[3][4]

The classic trap — hashitoxicosis. A minority of Hashimoto patients walk in thyrotoxic at the very start, from the initial burst of hormone release as follicles first rupture. It looks exactly like Graves — palpitations, tremor, weight loss — but there are no eye signs, the RAIU is low, and the antithyroid drugs you might reach for will do nothing. Give a beta-blocker for symptoms, then watch the patient slide into the hypothyroid phase they will occupy for life. ^[3]

Treatment is lifelong levothyroxine at a full replacement dose of about 1.6 mcg per kg per day — usually 75 to 100 mcg daily for women and 100 to 150 mcg for men — with the goal of normalising the serum TSH. Levothyroxine restores thyroid function tests to within the reference range and improves symptoms in the majority of patients. An euthyroid goitre with normal thyroid function may simply be observed. ^[12][5][4]

Everyone forgets — the lymphoma risk. Long-standing Hashimoto is the substrate for primary thyroid B-cell lymphoma, presenting as a rapidly enlarging goitre in a known Hashimoto patient. Any dominant or rapidly growing nodule in this background gets urgent fine-needle aspiration. ^[3][8]

Etymology for viva gold: the disease carries Hakaru Hashimoto's name — the Japanese surgeon who, in 1912, described "struma lymphomatosa" in Berlin. He died believing the paper had been ignored; it took forty years for the German-speaking world to catch up and attach his name to the commonest thyroiditis on earth. ^[3]

Subacute (de Quervain) — the painful one, and the one you must not miss

Subacute thyroiditis is the commonest cause of a painful thyroid: tender goitre, fever, high ESR, post-viral, low RAIU, self-limiting. It is unmistakable once seen, and misdiagnosed as pharyngitis or Graves when not. ^[1][10]

The picture is a painful, exquisitely tender goitre with pain radiating to the jaw or ear (referred otalgia is the classic clue), fever, malaise and fatigue, a preceding viral upper respiratory infection, and a transient thyrotoxic phase that evolves into a hypothyroid phase before recovery over weeks to months. The tenderness is so marked the patient cannot tolerate a collar or turn the head. Histology is granulomatous — follicular destruction with macrophages and multinucleated giant cells reacting to extravasated colloid. ^[1][10]

The triggers are the viruses you already know — coxsackievirus, mumps, echovirus, influenza, and increasingly SARS-CoV-2 infection and vaccination — and the demographic is women aged 20 to 50, with an annual incidence of about 12 per 100,000. ^[1][10]

The single test that nails it: a markedly raised ESR. The gland is swollen and tender with fever and an elevated erythrocyte sedimentation rate, while TSH is suppressed and T4/T3 raised — the classic split from Hashimoto. ^[23]

Management is NSAIDs (or aspirin) first-line, escalating to a glucocorticoid course if the disease is severe or protracted or NSAIDs fail — though recurrence may follow steroid withdrawal. A beta-blocker is used for thyrotoxic symptoms and thyroid hormone if the hypothyroid phase needs treating; initial prednisolone doses as low as 15 to 20 mg daily have proved effective with lower recurrence in a meta-analysis, while the traditional regimen is about 1 mg per kg daily tapered over around six weeks. ^{[23][10][16][17]}

Etymology for viva gold: Fritz de Quervain was the Swiss surgeon who distinguished this granulomatous form in 1904 — and whose name also attaches to the commonest wrist tenosynovitis. Two eponyms, one career. ^[1]

Postpartum and silent — the painless transient one you will miss

Postpartum and silent thyroiditis are painless, anti-TPO-positive, and run the classical curve — transient thyrotoxicosis, then hypothyroidism, then recovery — except in the roughly 25 percent who develop permanent hypothyroidism over the following decade. They masquerade as new-mother exhaustion or "just anxiety". ^[15][13]

The presentation is a painless, slightly firm goitre with the classical sequence: transient thyrotoxicosis (palpitations, anxiety, weight loss, heat intolerance) followed by hypothyroidism (fatigue, depression, dry skin, weight gain). Postpartum thyroiditis occurs within 12 months of delivery, typically 1 to 6 months postpartum; silent (sporadic) thyroiditis is the same process outside the puerperium. ^[6]

The numbers examiners ask: postpartum thyroiditis affects about 5 to 10 percent of women (reported series 5 to 9 percent), rising to 33 to 50 percent in women anti-TPO-positive in the first trimester; postpartum thyroid dysfunction reoccurs in about 75 percent of subsequent pregnancies, and about a quarter become permanently hypothyroid within ten years. Anti-TPO positivity in early pregnancy is the predictor — screen for it. ^[14][13][15]

Management is a short course of beta-blockers for the hyperthyroid phase when required; thyroid hormone replacement is reserved for women with TSH over 10 mU per L, or between 4 and 10 mU per L with symptoms or when attempting pregnancy, with long-term follow-up to catch the permanent-failure minority. The under-recognised hypothyroid phase is a quiet contributor to postnatal depression. ^[15][14]

Amiodarone — two diseases hiding in one tablet

Amiodarone is an iodine-rich drug — about 37 percent iodine by weight and structurally similar to the thyroid hormones. Deiodination releases large amounts of iodine that can impair thyroid function, causing either hypothyroidism or thyrotoxicosis in roughly a fifth of patients on the drug; the drug and its metabolite desethylamiodarone can also damage thyroid cells directly by cytotoxicity. ^[7]

Reported series put amiodarone-induced thyrotoxicosis itself at 7 to 15 percent of treated patients. Classically it takes two forms: type 1, iodine-induced thyrotoxicosis in a patient with an underlying abnormal thyroid, and type 2, drug-induced (destructive) thyroiditis in a "healthy" thyroid — determination of the type is a genuine diagnostic dilemma, because characteristics of both may coexist in the same patient. ^[11][7]

The classic trap — amiodarone type 1 versus type 2. They look similar at the bedside but the mechanisms differ, and management follows the type: ^[11][7]

^{[11] [7]}

Everyone forgets: mixed forms exist, and stopping amiodarone is a cardiologist-led decision, never an automatic one — the drug may be the only anti-arrhythmic option, and interrupting it is recommended mainly to improve the response to thioamides (type 1) and lower recurrence risk, while thyroidectomy is the fallback once AIT is under control. Amiodarone-induced hypothyroidism is managed with levothyroxine as for any hypothyroidism, and routine monitoring of thyroid function while on the drug is essential. ^[11][7][24]

The rare ones that bite — suppurative, Riedel, radiation, drugs

Acute suppurative thyroiditis is the bacterial abscess you must not miss, and Riedel is the woody fibrosis you must not cut. Both are rare, and both punish delay. ^[1]

Acute suppurative (infectious) thyroiditis is rare and far less common than subacute thyroiditis. It affects children and the immunocompromised, and a pyriform sinus fistula should be searched for, particularly in children with thyroiditis involving the left lobe. It presents as a tender, swollen gland with fever — a febrile disease mimicking subacute thyroiditis, which is exactly why ruling out the bacterial aetiology in any painful thyroid matters. Treat with antibiotics — specific once the organism and its sensitivities are identified, otherwise broad-spectrum — plus surgical drainage when necessary, then find and electively deal with the fistula to prevent recurrence. ^[23] Riedel thyroiditis is a chronic sclerosing replacement of the gland — histologically consistent with a localised form of IgG4-related systemic disease — in which dense fibrous tissue replaces the thyroid and extends to adjacent structures, causing dyspnoea, dysphagia and hoarseness from airway and local compression. The gland is stone-like, "hard as wood" and non-tender, and the process can also present with hypothyroidism, hypoparathyroidism or Horner syndrome. Glucocorticoids are the mainstay of treatment and can produce dramatic improvement — the historical surgical approach has given way to medical therapy, with tamoxifen, mycophenolate and radiation as alternatives when steroids fail, and surgery reserved for airway compression or failed medical therapy (the fibrosis makes any surgical intervention very difficult). ^[9][21][23]

Radiation thyroiditis (after radioactive iodine therapy or external neck radiotherapy) and trauma or palpation thyroiditis cause a self-limiting thyrotoxic leak and need only a beta-blocker if symptomatic. Lithium impairs hormone release and raises goitre and hypothyroidism risk; interferon-alpha, interleukin-2, tyrosine-kinase inhibitors (sunitinib, sorafenib) and immune checkpoint inhibitors (pembrolizumab, nivolumab, ipilimumab) all trigger autoimmune or destructive thyroiditis in a meaningful minority — manage as for Hashimoto or silent thyroiditis and continue the immunotherapy with endocrine input where possible. ^[1]

The goitre — diffuse or nodular, toxic or not

A goitre is simply an enlarged thyroid; classify it on two axes — function (TSH) and structure (diffuse versus nodular) — and the management follows. The epidemiology splits the world: in iodine-sufficient regions autoimmune Hashimoto dominates; worldwide, iodine deficiency still leads. ^[1][5] A goitre is an enlarged thyroid, identified by palpation or, on ultrasound, by a thyroid volume above the upper reference limit — about 18 mL in women and 25 mL in men. These limits vary with age, body weight, body height and iodine status — in one large adult population previously deficient in iodine, individualised equations cut the prevalence of "goitre" from about a third to 7 percent. It is classified by morphology (diffuse versus nodular, uni- or multinodular), by function (toxic versus non-toxic), and by epidemiology (endemic — iodine deficiency in a region — versus sporadic). ^[22][5]

The WHO grades goitre clinically: grade 0 (no goitre), grade 1 (palpable but not visible with the neck in normal position), grade 2 (visible at normal posture). A region is endemic when goitre prevalence exceeds 10 percent in school-age children. A retrosternal (substernal) goitre extends below the thoracic inlet and is a surgical concern because of the rigid bony thoracic inlet. ^[5]

The numbers examiners reach for first: ^[1]

^{[13] [14] [15] [11] [7] [22] [12]}

Endemic goitre from iodine deficiency is the leading worldwide cause: the gland, unable to iodinate thyroglobulin adequately, falls under TSH hyperstimulation and undergoes diffuse then nodular hyperplasia, and over decades a simple diffuse goitre evolves into a multinodular one that may become autonomous and toxic. Universal salt iodisation (ICMR and NIDDCP programmes) is the public-health cornerstone and has eliminated endemic cretinism across much of India and the developing world. ^[5]

A diffuse non-toxic goitre is driven by iodine deficiency, Hashimoto, Graves, the physiological goitre of puberty and pregnancy (high hCG acts on the TSH receptor), dyshormonogenesis, or simple colloid goitre. A multinodular goitre is nodular hyperplasia — toxic when autonomous nodules suppress TSH, compressive when it grows into the thoracic inlet. The three thyrotoxic goitres split like this: ^[1][2]

^[1]

Enlarge

Read the bedside feel of the neck — the feel predicts the diagnosis

Palpation is the bedside test that predicts the diagnosis before any bloods return. Examine from in front: inspect for swellings, then ask the patient to swallow — a thyroid swelling moves up with swallowing, distinguishing it from thyroglossal and other neck swellings. ^[2][3]

• A firm, rubbery, diffuse, non-tender gland with a lobulated surface suggests Hashimoto.
• An exquisitely tender, firm gland with overlying warmth suggests subacute thyroiditis (gently palpate — the patient will wince; pain may radiate to the ear).
• A stony-hard, fixed mass invading adjacent structures, not moving well on swallowing, suggests Riedel thyroiditis or malignancy.
• A soft, smooth, diffuse swelling with a bruit suggests Graves.
• A nodular gland with multiple lumps suggests multinodular goitre.
• A fluctuant, warm, erythematous tender swelling in an unwell child suggests acute suppurative thyroiditis. ^[1]

Pemberton's manoeuvre is the bedside sign for a retrosternal goitre. Ask the patient to raise both arms above the head until they touch the ears and hold the position; facial plethora, distension of the neck veins, stridor or distress within 30 to 60 seconds indicates a retrosternal goitre causing thoracic-inlet obstruction — a positive Pemberton sign mandates cross-sectional imaging and surgical referral. ^[2]

Look specifically for the signs that separate Graves from thyroiditis — exophthalmos (proptosis), lid retraction and lid lag, and ophthalmoplegia — and for tracheal deviation (best felt at the suprasternal notch), cervical lymphadenopathy (a red flag for malignancy) and hoarseness (recurrent laryngeal nerve involvement — also a malignancy red flag). A compressive goitre causes dysphagia, stridor, dyspnoea, a choking sensation lying flat, a Pemberton sign, and occasionally superior vena cava obstruction. ^[2][8]

First-line investigations — TSH, anti-TPO, ESR, RAIU

Thyroid function tests interpreted by phase are the first line; anti-TPO, ESR and RAIU are the discriminators. The TFT pattern depends on where in the triphasic curve the patient sits. ^[1][5]

• Thyrotoxic phase — suppressed TSH (below 0.1 mIU per L) with raised free T4 and free T3 (hormone leaking from the damaged gland). The TSH is the most sensitive marker.
• Hypothyroid phase — raised TSH with low free T4 (the gland store is exhausted and synthesis is impaired).
• Recovery — TFTs normalise as the gland regenerates. In Hashimoto the patient lands in the hypothyroid phase and stays there. ^[1]

Antibodies split the autoimmune forms: anti-TPO is positive in Hashimoto (over 90 percent), postpartum and silent thyroiditis and predicts permanent hypothyroidism, whereas TSH-receptor antibodies (TRAb) are the hallmark of Graves and are negative in thyroiditis. A TRAb level is the single most useful test to separate Graves from a destructive thyroiditis when RAIU is not available. ^[3][6]

Inflammatory markers are the key clue in subacute disease: the gland is swollen and tender with fever and an elevated erythrocyte sedimentation rate (CRP was raised in 86.5 percent of a verified Danish cohort) — the favourite exam split from the painless thyroiditides. ^[23][26]

Radioactive iodine uptake (RAIU, iodine-123 or technetium-99m scan) is the decisive discriminator: scintigraphy is one of the four tools that pin down the cause of hyperthyroidism — a diminished thyroidal RAIU marks subacute and other destructive thyroiditides, while Graves and toxic nodular disease overproduce with high uptake. Amiodarone thyrotoxicosis needs the type-1 versus type-2 clinical and biochemical separation, since the type determination is a recognised diagnostic dilemma. ^[1][2][11]

Thyroid ultrasound shows heterogeneous hypoechogenicity in Hashimoto (often pseudo-nodular with increased vascularity), a swollen hypoechoic gland in subacute thyroiditis, and characterises nodules by TI-RADS. Fine-needle aspiration is indicated for a dominant or suspicious nodule (TI-RADS-guided), a rapidly enlarging goitre, or a dominant nodule in long-standing Hashimoto (to exclude lymphoma or papillary cancer) — it is not needed for a classic tender subacute thyroiditis. ^[3][8]

Cross-sectional imaging (CT or MRI) defines a retrosternal goitre's extent, tracheal compression and great-vessel relationship before surgery, and maps fibrosis in Riedel. Laryngoscopy checks vocal-cord function before any thyroid surgery; calcium is checked in Riedel for parathyroid infiltration. ^[2][9]

Thyroid storm is a clinical diagnosis, supported by the Burch-Wartofsky point score (BWPS), where a score of 45 or above is highly indicative of storm — points for thermoregulatory, CNS, gastrointestinal-hepatic, cardiac and precipitant dysfunction on a background of decompensated thyrotoxicosis. ^[20][18]

The management ladder — treat the type and the phase

In destructive thyroiditis the thyrotoxic phase is treated with a beta-blocker; the hormone is leaking, not being made. Synthetic thyrotoxicosis (Graves, toxic multinodular goitre, toxic adenoma) needs antithyroid drugs, radioiodine or surgery. ^[1][2]

Enlarge

The type-and-phase ladder, drug by drug: ^[1]

• Destructive thyroiditis, thyrotoxic phase — a beta-blocker for symptom control. Antithyroid drugs are not used — the destructive thyrotoxicosis is usually mild and transient, and steroids are reserved for severe cases. ^[1]
• Subacute (de Quervain) — NSAIDs (or aspirin) first-line, with rest and thyroid hormone if needed; glucocorticoids if the disease is severe or protracted (recurrence may follow their withdrawal); an initial low prednisolone dose of 15 to 20 mg daily is effective with lower recurrence than higher initial doses, while the traditional regimen is about 1 mg per kg daily tapered over around six weeks. ^[23][16][17]
• Hashimoto — lifelong levothyroxine at a full replacement dose of about 1.6 mcg per kg per day (75 to 100 mcg daily for women, 100 to 150 mcg for men), titrated to a normal TSH. ^[12][3]
• Postpartum and silent — a short course of beta-blockers for the hyperthyroid phase when required; thyroid hormone replacement for TSH over 10 mU per L, or 4 to 10 mU per L with symptoms or when attempting pregnancy, with long-term follow-up. ^[15]
• Acute suppurative — antibiotics, specific once the organism is identified or broad-spectrum otherwise, plus surgical drainage when necessary; search for and deal with a pyriform sinus fistula, particularly with left-lobe involvement in children. ^[23]
• Amiodarone — type 1 responds to thioamides, ideally with amiodarone interrupted to improve the response; type 2 usually resolves with medical management and amiodarone can often be continued or re-introduced; thyroidectomy once the thyrotoxicosis is under control when the drug must continue; hypothyroidism is replaced with levothyroxine. ^[11][7]
• Riedel — glucocorticoids first-line (dramatic improvement is possible), with tamoxifen, mycophenolate or radiation as alternatives; surgery for airway compression or failed medical therapy. ^[9][21]

For the goitre itself, the ladder runs from observation to surgery: ^[2][8]

• An asymptomatic, non-toxic diffuse goitre with normal TSH and no suspicious nodule is observed with periodic ultrasound. Suppressive levothyroxine is controversial and not routinely recommended — it does not reliably shrink a non-toxic goitre and risks iatrogenic thyrotoxicosis and bone loss.
• A toxic multinodular goitre is treated with radioactive iodine (preferred in older or unfit patients) or surgery (near-total or total thyroidectomy) for large compressive goitres, those with a suspicious nodule, or younger patients; a brief thionamide course before radioiodine reduces the small risk of storm.
• A compressive or retrosternal goitre (dysphagia, stridor, Pemberton sign, tracheal narrowing) is referred for surgery.
• A solitary nodule is worked up by ultrasound and TI-RADS with FNA if indicated, and managed by the Bethesda cytology category — benign observe, indeterminate molecular testing or diagnostic lobectomy, malignant thyroidectomy. Percutaneous ethanol injection is an option for recurrent benign cystic nodules.
• Iodine supplementation is the definitive and preventive treatment for endemic iodine-deficiency goitre. ^[2][8]

Thyroid storm — the resuscitation scenario

Thyroid storm is the decompensation of thyrotoxicosis: multiple organ failure due to severe thyrotoxicosis, usually with a triggering illness — an endocrine emergency whose fatality rate in older series ran between 20 and 50 percent. It is a clinical diagnosis, supported by the Burch-Wartofsky score. ^[18][19]

Recognise it from exaggerated signs and symptoms of hyperthyroidism with multiorgan decompensation — fever, severe tachycardia or atrial fibrillation, heart failure, CNS disturbance (agitation, delirium, coma) and gastrointestinal-hepatic dysfunction — usually occurring in the presence of an inciting trigger such as infection, surgery, an iodine load or antithyroid-drug withdrawal. ^[18][19]

Admit to ICU and give multimodal therapy — each drug class blocks a different step in synthesis, release and peripheral action, and the combination has been shown to improve mortality: ^[18]

• Supportive — ICU-level care, treat the precipitating illness, and supportive therapies directed at the organ systems affected. ^[18]
• Block synthesis — a thionamide. Antithyroid drugs are the synthetic-blocker arm of the bundle; guidelines recommend them as one of the four pillars. ^[18]
• Block release — inorganic iodide, added to the thionamide as the second pillar. ^[18]
• Block peripheral action and support the adrenal axis — corticosteroids. ^[18]
• Block adrenergic symptoms — a beta-adrenergic antagonist. ^[18]
• Refractory cases — patients who fail medical therapy are treated with therapeutic plasma exchange or thyroidectomy; modern series report mortality around 10 percent, a large improvement on the historical 20 to 50 percent. ^[25][19]

Complications and the preventable-harm list

Untreated thyrotoxicosis of any cause drives atrial fibrillation, thromboembolic stroke, high-output then dilated (thyrotoxic) heart failure, osteoporosis, weight loss and proximal myopathy — and at the extreme, thyroid storm. A large goitre compresses the airway, oesophagus and great veins, and any dominant nodule may harbour papillary carcinoma or, in long-standing Hashimoto, a primary thyroid B-cell lymphoma. ^[1][3][8]

The classic pitfalls that lose marks and harm patients: ^[1][2]

1. Giving antithyroid drugs to the thyrotoxic phase of thyroiditis — the gland is leaking, not synthesising; use a beta-blocker.
2. Missing subacute thyroiditis by not checking the ESR or not eliciting tenderness; it is then mislabelled pharyngitis or Graves.
3. Mislabelling amiodarone type 2 (destructive) as type 1 and treating with thionamides when steroids are needed — and vice versa.
4. Failing to biopsy a dominant or rapidly enlarging nodule, missing lymphoma or papillary cancer.
5. Treating a painless thyroiditis like Graves with antithyroid drugs or radioiodine.
6. Forgetting that RAIU is the single test that separates destructive thyroiditis from Graves.
7. Missing retrosternal extension by not performing Pemberton's manoeuvre, and sending a patient with tracheal compression for surgery without cross-sectional imaging. ^[1][2]

Most destructive thyroiditis is self-limiting — subacute, postpartum and silent recover, though a quarter of postpartum thyroiditis patients become permanently hypothyroid within a decade and some subacute patients are left hypothyroid. Hashimoto is lifelong but excellent once levothyroxine is established; thyroid storm carries high mortality even with treatment and mandates ICU. Disposition: outpatient with serial TSH for stable thyroiditis; surgical referral for compressive or retrosternal goitre, a suspicious nodule, or Riedel with compression; ICU for storm; inpatient for acute suppurative thyroiditis. ^[15][1][6]

Special populations

• Postpartum women — screen anti-TPO-positive women; postpartum thyroiditis affects about 5 to 10 percent of women (33 to 50 percent of those anti-TPO-positive in the first trimester), reoccurs in about 75 percent of subsequent pregnancies, and leaves roughly a quarter permanently hypothyroid within ten years — so monitor thyroid function long-term. ^[14][13][15]
• Amiodarone-treated patients — monitor thyroid function routinely while on the drug; thyrotoxicosis is typically severe, resists anti-thyroid measures and negatively affects cardiac status, so it warrants prompt, type-specific treatment. ^[24][11]
• Iodine-deficient populations — endemic goitre and cretinism; universal salt iodisation is the public-health cornerstone, and adequate iodine in pregnancy and early childhood prevents the irreversible neurodevelopmental harm of endemic cretinism. ^[5]
• The elderly with toxic MNG — may present apathetically with atrial fibrillation, weight loss, heart failure and depression rather than agitation; treat cautiously with beta-blockade and radioactive iodine, often after a brief thionamide course to render them biochemically safer. ^[2]
• Pregnancy — radioactive iodine is absolutely contraindicated; a symptomatic thyrotoxic phase of thyroiditis is managed with the lowest effective beta-blocker for the shortest time, and overt hypothyroidism is treated with levothyroxine to trimester-specific TSH targets (first-trimester TSH below 2.5 mIU per L). Physiological goitre of pregnancy needs no treatment. ^[6]
• Children — acute suppurative thyroiditis is over-represented; think of a pyriform sinus fistula and arrange imaging for elective excision after the acute episode. Congenital dyshormonogenetic goitre presents with a goitre and hypothyroidism from birth. ^[5]

Guidelines and the regional picture

The ATA 2016 hyperthyroidism guideline (Ross et al.) sets the standard for Graves, toxic MNG or adenoma, the destructive thyroiditides, amiodarone-induced thyrotoxicosis and thyroid storm, formalising RAIU as the discriminator and the ordered storm bundle. The ATA 2017 pregnancy and postpartum guideline (Alexander et al.) addresses postpartum thyroiditis — anti-TPO screening, monitoring, and the recognition that a substantial minority become permanently hypothyroid. The ATA 2015 nodule guideline (Haugen et al.) codifies the ultrasound TI-RADS score and the size-based FNA thresholds. ^[2][6][8]

The Lancet and Lancet Diabetes and Endocrinology reviews by Taylor (hypothyroidism) and Wiersinga (hyperthyroidism) synthesise global epidemiology and pathogenesis — confirming Hashimoto as the dominant cause in iodine-sufficient regions and iodine deficiency as the dominant cause worldwide. The Riedel or IgG4 reviews consolidate the modern understanding of Riedel thyroiditis as an IgG4-related fibrosing disease, justifying glucocorticoid and tamoxifen therapy. ^[1][5][9]

Regional picture: in iodine-sufficient regions the burden of goitre and hypothyroidism is autoimmune (Hashimoto), whereas iodine deficiency remains the dominant cause across much of India and the developing world — addressed by universal salt iodisation. A paradox worth knowing: iodine repletion in a previously deficient population transiently increases the incidence of autoimmune thyroiditis and Jod-Basedow thyrotoxicosis, as the now-abundant iodine fuels autoimmune destruction and autonomous nodules. ^[1][5]

The memory devices

Cluster the thyroiditides by pain and you hold the fastest bedside discriminator. ^[1]

^[1]

The cluster rule for the painful neck: painful thyroid plus high ESR plus low RAIU is subacute; painful thyroid plus a septic child and a left-lobe abscess is suppurative; a sudden painful nodule overnight is haemorrhage into a cyst. ^[1]

The mantra, once more: low uptake, beta-blocker; high uptake, antithyroid. ^[1]

Ward-round test

Stem 1 — the painful neck. A 40-year-old man has a painful tender thyroid radiating to his ear, fever and palpitations two weeks after a flu-like illness. TSH is suppressed, free T4 is high, ESR is 64 mm per hour. What is the diagnosis, the confirming test, and the first-line and escalation treatment? ^[1]

RevealShowHide

This is subacute (de Quervain) thyroiditis — the painful thyroiditis, post-viral, with a swollen tender gland, fever and an elevated ESR. A diminished thyroidal radioactive iodine uptake confirms the destructive (leak) mechanism versus Graves. First-line is NSAIDs (or aspirin), with a beta-blocker for thyrotoxic symptoms; if the disease is severe or protracted, escalate to a glucocorticoid course — initial prednisolone doses as low as 15 to 20 mg daily work with less recurrence, while the traditional schedule is about 1 mg per kg daily tapered over around six weeks. ^[23][16][17]

Stem 2 — the painless postpartum neck. A 29-year-old, four months postpartum, has palpitations and weight loss for two weeks, then fatigue and low mood. Her thyroid is painless and slightly firm, anti-TPO is positive, TSH is suppressed. What is the diagnosis, the confirming mechanism test, and the first drug? ^[6]

RevealShowHide

This is postpartum thyroiditis — the painless, anti-TPO-positive, transient form within the first year after delivery. A low radioactive iodine uptake confirms the destructive mechanism versus Graves. Reach for a short course of beta-blockers for the thyrotoxic phase — not antithyroid drugs — and reserve thyroid hormone for TSH over 10 mU per L (or 4 to 10 with symptoms or when trying to conceive), with long-term follow-up as roughly a quarter become permanently hypothyroid. ^[15][13]

Stem 3 — amiodarone and a tremor. A 68-year-old man on amiodarone for atrial fibrillation presents with new tremor, weight loss and worsening heart failure. TSH is suppressed, free T4 is high. How do you tell type 1 from type 2, and why does it matter? ^[7]

RevealShowHide

This is amiodarone-induced thyrotoxicosis. Distinguishing type 1 — iodine-induced thyrotoxicosis in an underlying abnormal thyroid — from type 2 — drug-induced destructive thyroiditis in a "healthy" thyroid is a genuine diagnostic dilemma, because features of both may coexist. It matters because management differs: type 1 responds to thionamides (and interrupting amiodarone improves that response and lowers recurrence risk), while after type 2 amiodarone can often be continued or safely re-introduced; when the drug is indispensable and the thyrotoxicosis uncontrolled, thyroidectomy once the AIT is controlled is the definitive route. ^[11][7]

Stem 4 — the storm. A thyrotoxic patient arrives in the emergency department with a temperature of 40.5 degrees C, atrial fibrillation at 150, agitation and vomiting. What is the diagnosis, and give the drug bundle in order. ^[2]

RevealShowHide

This is thyroid storm — a clinical diagnosis; a Burch-Wartofsky score of 45 or above is highly indicative. Admit to ICU and give multimodal therapy: a thionamide, inorganic iodide, corticosteroid and beta-adrenergic antagonist, with treatment of the precipitant and organ support throughout — patients who fail medical therapy go to plasma exchange or thyroidectomy. ^[20][18][25]

References26ShowHide

1. [1]Wiersinga WM, Poppe KG, Effraimidis G. Hyperthyroidism: aetiology, pathogenesis, diagnosis, management, complications, and prognosis Lancet Diabetes Endocrinol, 2023.PMID 36848916
2. [2]Ross DS, Burch HB, Cooper DS, et al. 2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis Thyroid, 2016.PMID 27521067
3. [3]Ralli M, Angeletti D, Fiore M, et al. Hashimoto's thyroiditis: An update on pathogenic mechanisms, diagnostic protocols, therapeutic strategies, and potential malignant transformation Autoimmun Rev, 2020.PMID 32805423
4. [4]Liontiris MI, Mazokopakis EE. A concise review of Hashimoto thyroiditis (HT) and the importance of iodine, selenium, vitamin D and gluten on the autoimmunity and dietary management of HT patients.Points that need more investigation Hell J Nucl Med, 2017.PMID 28315909
5. [5]Taylor PN, Medici MM, Hubalewska-Dydejczyk A, et al. Hypothyroidism Lancet, 2024.PMID 39368843
6. [6]Alexander EK, Pearce EN, Brent GA, et al. 2017 Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and the Postpartum Thyroid, 2017.PMID 28056690
7. [7]Ylli D, Wartofsky L, Burman KD. Evaluation and Treatment of Amiodarone-Induced Thyroid Disorders J Clin Endocrinol Metab, 2021.PMID 33159436
8. [8]Haugen BR, Alexander EK, Bible KC, et al. 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer Thyroid, 2016.PMID 26462967
9. [9]Czarnywojtek A, Pietrończyk K, Thompson LDR, et al. IgG4-related sclerosing thyroiditis (Riedel-Struma): a review of clinicopathological features and management Virchows Arch, 2023.PMID 37204493
10. [10]Saydam BO, Adiyaman SC, Demir T, et al. The use of low dose prednisolone in patients with subacute thyroiditis and its effect on impaired life and sleep quality Acta Endocrinol (Buchar), 2022.PMID 35975250
11. [11]Maqdasy S, Benichou T, Dallel S, et al. Issues in amiodarone-induced thyrotoxicosis: Update and review of the literature Ann Endocrinol (Paris), 2019.PMID 30236455
12. [12]Mandel SJ, Brent GA, Larsen PR. Levothyroxine therapy in patients with thyroid disease Ann Intern Med, 1993.PMID 8357116
13. [13]Lazarus JH, Parkes AB, Premawardhana LD. Postpartum thyroiditis Autoimmunity, 2002.PMID 12389641
14. [14]Stagnaro-Green A. Recognizing, understanding, and treating postpartum thyroiditis Endocrinol Metab Clin North Am, 2000.PMID 10874538
15. [15]Stagnaro-Green A. Postpartum thyroiditis Best Pract Res Clin Endocrinol Metab, 2004.PMID 15157842
16. [16]Soltani A, Nourani F, Roudsari SB, et al. Identifying the Lowest Effective Initial Dose of Prednisolone for the Treatment of Subacute Granulomatous Thyroiditis: A Systematic Review and Meta-Analysis Curr Rev Clin Exp Pharmacol, 2022.PMID 34636318
17. [17]Koirala KP, Sharma V. Treatment of Acute Painful Thyroiditis with Low Dose Prednisolone: A Study on Patients from Western Nepal J Clin Diagn Res, 2015.PMID 26500930
18. [18]Satoh T, Isozaki O, Suzuki A, et al. 2016 Guidelines for the management of thyroid storm from The Japan Thyroid Association and Japan Endocrine Society (First edition) Endocr J, 2016.PMID 27746415
19. [19]Burch HB, Wartofsky L. Life-threatening thyrotoxicosis. Thyroid storm Endocrinol Metab Clin North Am, 1993.PMID 8325286
20. [20]Austin CP, Odak M, Douedi S, Patel SV. Supraventricular Tachycardia: An Atypical Presentation of Thyroid Storm Cureus, 2022.PMID 35774700
21. [21]Gosi SKY, Nguyen M, Garla VV. Riedel Thyroiditis StatPearls, 2026.PMID 30725988
22. [22]Ittermann T, Angelow A, Chenot JF, et al. Thyroid volume-new reference values for defining thyroid enlargement Eur J Endocrinol, 2025.PMID 40424555
23. [23]Majety P, Hennessey JV. Acute and Subacute, and Riedel's Thyroiditis Endotext, 2000.PMID 25905408
24. [24]Oktaviono YH, Mustofa A, Saputra PBT, et al. Exploring Current Diagnosis and Management of Amiodarone-induced Thyrotoxicosis Am J Cardiol, 2025.PMID 39924094
25. [25]Chiha M, Samarasinghe S, Kabaker AS. Thyroid storm: an updated review J Intensive Care Med, 2015.PMID 23920160
26. [26]Kjellerup CR, Thomsen MJ, Torp NMU, et al. Characteristics of patients with subacute thyroiditis Dan Med J, 2023.PMID 37897374