side by side comparison
Thyroid Storm vs Myxedema Coma: The Two Thyroid Emergencies
A delirious patient with a temp of 105°F and a heart rate of 160 needs the exact opposite intervention from an obtunded patient at 94°F with a heart rate of 42. These two thyroid emergencies mirror each other — every vital sign, every symptom, every drug is reversed. Pick the wrong one on the NCLEX and you accelerate the crisis.
Comparison
Side-by-side2 compared
Dimension
Thyroid Storm
Myxedema Coma
Pathophysiology & risk
- Extreme hyperthyroidism (↑↑ T3/T4, ↓ TSH)
- Trigger: infection, surgery, abrupt drug stop, iodine
- Extreme hypothyroidism (↓↓ T3/T4, ↑ TSH)
- Trigger: infection, cold, sedatives, noncompliance
Signs & symptoms
- ★Hyperthermia > 104°F (40°C)
- Severe tachycardia 140–180; AFib
- Agitation → delirium → seizures → coma
- ★Hypothermia < 95°F (35°C)
- Bradycardia 40–60; heart block risk
- Lethargy → obtundation → coma; hypoventilation
Diagnostics & labs
- ↑↑ free T3/T4, ↓ TSH
- Hyperglycemia, ↑ LFTs
- ↓↓ free T3/T4, ↑ TSH
- Hyponatremia + hypoglycemia
Nursing priorities
- ★Aggressive cooling (blankets, ice packs)
- Avoid ASA (displaces T4); IV fluids; telemetry
- ★Passive rewarming only — active → collapse
- Support airway/ventilation; cautious IV fluids
Treatment & meds
- Propranolol (rate; blocks T4→T3)
- PTU/methimazole; iodine 1 hr after; hydrocortisone
- IV levothyroxine loading dose
- IV hydrocortisone; cautious glucose correction
Patient teaching
- Take antithyroid meds; never stop abruptly
- Know storm triggers (infection, stress)
- Lifelong levothyroxine; never skip
- Avoid sedatives/opioids; dress warm
Red flags — escalate
- Temp > 106°F; AFib with RVR; seizures
- Respiratory failure (CO₂ narcosis)
- Profound bradycardia / heart block
Complications
- High-output heart failure; arrhythmia; death
- Respiratory failure; refractory hypotension; death
Pathophysiology & risk
Thyroid Storm
- Extreme hyperthyroidism (↑↑ T3/T4, ↓ TSH)
- Trigger: infection, surgery, abrupt drug stop, iodine
Myxedema Coma
- Extreme hypothyroidism (↓↓ T3/T4, ↑ TSH)
- Trigger: infection, cold, sedatives, noncompliance
Signs & symptoms
Thyroid Storm
- ★Hyperthermia > 104°F (40°C)
- Severe tachycardia 140–180; AFib
- Agitation → delirium → seizures → coma
Myxedema Coma
- ★Hypothermia < 95°F (35°C)
- Bradycardia 40–60; heart block risk
- Lethargy → obtundation → coma; hypoventilation
Diagnostics & labs
Thyroid Storm
- ↑↑ free T3/T4, ↓ TSH
- Hyperglycemia, ↑ LFTs
Myxedema Coma
- ↓↓ free T3/T4, ↑ TSH
- Hyponatremia + hypoglycemia
Nursing priorities
Thyroid Storm
- ★Aggressive cooling (blankets, ice packs)
- Avoid ASA (displaces T4); IV fluids; telemetry
Myxedema Coma
- ★Passive rewarming only — active → collapse
- Support airway/ventilation; cautious IV fluids
Treatment & meds
Thyroid Storm
- Propranolol (rate; blocks T4→T3)
- PTU/methimazole; iodine 1 hr after; hydrocortisone
Myxedema Coma
- IV levothyroxine loading dose
- IV hydrocortisone; cautious glucose correction
Patient teaching
Thyroid Storm
- Take antithyroid meds; never stop abruptly
- Know storm triggers (infection, stress)
Myxedema Coma
- Lifelong levothyroxine; never skip
- Avoid sedatives/opioids; dress warm
Red flags — escalate
Thyroid Storm
- Temp > 106°F; AFib with RVR; seizures
Myxedema Coma
- Respiratory failure (CO₂ narcosis)
- Profound bradycardia / heart block
Complications
Thyroid Storm
- High-output heart failure; arrhythmia; death
Myxedema Coma
- Respiratory failure; refractory hypotension; death
★ marks the fact that sets a column apart.
Clinical Pearl
Storm = hot, fast, wild — cool down and beta-block. Myxedema = cold, slow, silent — warm up and give IV T4.
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