Endocrinology · PANCE / PANRE

Thyroid Storm

Life-threatening hyperthyroidism with multisystem decompensation; mortality 10-30%.

Also known as: thyroid storm, thyrotoxic crisis, thyrotoxic storm

Overview

Severe, life-threatening exacerbation of thyrotoxicosis characterized by hyperpyrexia, marked tachycardia, CNS dysfunction, and multi-organ decompensation. Clinical diagnosis (Burch-Wartofsky Point Scale) — do not wait for thyroid function tests to act.

Epidemiology

Uncommon (<10% of hospitalized thyrotoxic patients), but mortality 10-30%. Most cases occur in patients with known or unrecognized Graves disease or toxic nodular goiter. Often precipitated by an identifiable trigger.

🔒 Free preview limit reached

Keep reading — start your free trial

You've read your 2 free diagnosis previews. Create your free account to unlock the full Thyroid Storm outline — plus all 514 diagnoses, 3,500+ board-style questions, flashcards, and an AI tutor. Your 7-day free trial includes everything, and there's no credit card required.

Start your 7-day free trial → Sign in

Free to start · No credit card · Cancel anytime

Risk factors

Underlying Graves disease (most common), toxic multinodular goiter, toxic adenoma
Precipitants: infection, surgery (thyroid or non-thyroid), trauma, MI, stroke, DKA, parturition
Iodine load (contrast, amiodarone), thionamide non-adherence or discontinuation
RAI therapy in inadequately blocked patient
Vigorous palpation of an unprepared thyroid

Pathophysiology

Acute elevation of free thyroid hormone combined with increased tissue responsiveness produces a hypermetabolic crisis. Increased beta-adrenergic receptor sensitivity drives tachycardia, fever, and CNS hyperactivity. Cytokine release from a precipitating stressor compounds systemic decompensation.

Clinical presentation

Symptoms

Marked agitation, delirium, psychosis, seizure, or coma
Profuse sweating, drenched bedding
Severe nausea, vomiting, diarrhea, abdominal pain
Palpitations, chest pain, dyspnea
History of recent thyroid surgery, radioiodine, or noncompliance with thionamides

Signs / physical exam

Hyperpyrexia (often >40°C), drenching diaphoresis
Sinus tachycardia >140 or atrial fibrillation with rapid response, hypertension followed by hypotension/shock
Jaundice (poor prognostic sign), hepatomegaly
Goiter ± thyroid bruit, exophthalmos (Graves)
Pulmonary edema, signs of high-output heart failure

Classic findings

Burch-Wartofsky Point Scale (BWPS): score ≥45 highly suggestive, 25-44 impending storm, <25 unlikely. Domains: temperature, CNS, GI/hepatic, CV (tachycardia/CHF/AF), precipitating event.

Differential diagnosis

Sepsis — Fever, tachycardia, AMS overlap; obtain cultures and treat empirically; storm can coexist
Heat stroke — Hot dry skin, exertional or environmental exposure; treat with cooling
Neuroleptic malignant syndrome — Antipsychotic exposure, lead-pipe rigidity, elevated CK
Serotonin syndrome — Serotonergic drug exposure, clonus, hyperreflexia
Malignant hyperthermia — Anesthetic trigger, masseter rigidity, hypercarbia; treat with dantrolene
Pheochromocytoma crisis — Episodic hypertension, headache, sweating; metanephrines
Cocaine/sympathomimetic toxicity — Drug exposure history, mydriasis, hypertension
Acute alcohol or sedative withdrawal — Tremor, tachycardia, agitation; benzodiazepine response

Diagnostic workup

Diagnostic criteria

Clinical diagnosis using BWPS or Japanese Thyroid Association criteria. Don't wait for hormone levels.

Labs

TSH (suppressed), free T4, free T3 (markedly elevated) — confirm diagnosis but do not delay treatment
CBC, CMP (LFTs often elevated, hyperglycemia, hypercalcemia), coagulation studies
Cardiac troponin, BNP, lactate
Blood cultures, urinalysis, lipase if abdominal symptoms
Pregnancy test in reproductive-age women

Imaging

ECG (sinus tachycardia, AFib, ischemia)
CXR (heart failure, pneumonia)
Identify and image precipitant (CT for infection, abdomen, or trauma as indicated)

Diagnostic algorithm

Step	Agent	Dose	Mechanism
1	Propranolol	60-80 mg PO q4h or 0.5-1 mg IV	Blocks adrenergic effects + T4→T3 conversion
2	PTU (preferred) or methimazole	PTU 500-1000 mg load then 250 mg q4h	Blocks new hormone synthesis (+ T4→T3 for PTU)
3 (≥1 h after #2)	SSKI / Lugol's iodine	SSKI 5 drops PO q6h	Blocks hormone RELEASE (Wolff-Chaikoff)
4	Hydrocortisone or dexamethasone	Hydrocort 100 mg IV q8h or dex 2 mg q6h	Blocks T4→T3, treats relative adrenal insufficiency
5	Supportive	Cooling, IVF, treat trigger	Acetaminophen NOT aspirin; ICU

Thyroid storm treatment sequence — order matters (iodine must follow thionamide by ≥1 hour).

Complications

High-output heart failure, atrial fibrillation, embolic stroke
Multi-organ failure, hepatic failure (jaundice carries poor prognosis)
Shock and death (mortality 10-30%)
Seizure, coma
Adrenal crisis if cortisol not co-administered

PANCE pearls

ORDER MATTERS: beta-blocker first, then thionamide, then iodine AT LEAST 1 hour later (iodine before thionamide can fuel synthesis), then steroids.
PTU > methimazole in storm because PTU blocks peripheral T4→T3 conversion.
Acetaminophen for fever — never aspirin, which displaces thyroid hormone from binding proteins and worsens the crisis.
Burch-Wartofsky ≥45 = highly likely storm. Don't wait for TFTs to start treatment.
Look for the precipitant — infection is the most common trigger and must be identified and treated.

References

ATA 2016 — 2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism — Thyroid Storm section (Ross et al., Thyroid 2016)
Burch & Wartofsky 1993 — Life-Threatening Thyrotoxicosis: Thyroid Storm (Burch & Wartofsky, Endocrinol Metab Clin North Am 1993)
JTA 2016 — Japan Thyroid Association Guidelines for the Management of Thyroid Storm (Satoh et al., Endocr J 2016)

Practice Endocrinology questions on FirstPassPA

Turn this outline into retention. 3,500+ board-style questions with an AI tutor that explains every answer — free to start, no card required.

Start studying free → Browse all 514 diagnoses

Educational use only. This outline is a study aid for PA students and is not medical advice or a substitute for clinical judgment. FirstPassPA is an independent study tool and is not affiliated with, endorsed by, or sponsored by NCCPA. PANCE® and PANRE® are registered trademarks of the National Commission on Certification of Physician Assistants.