Med-Surg · Endocrine
Thyroid Disorders
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Prepared for Pass the Shift (owner: Kristina, RN). Always follow your facility’s protocols, provider orders, and current drug references.
1. Overview and Pathophysiology
The thyroid produces T4/T3 under TSH control (pituitary). These hormones set metabolic rate.
| Disorder | Metabolic state | Common causes |
|---|---|---|
| Slowed metabolism | Hashimoto thyroiditis, iodine deficiency, post-ablation/surgery, drugs (lithium, amiodarone) | |
| Accelerated metabolism | Graves disease, toxic nodule/goiter, thyroiditis phases | |
| Thyroid storm | Life-threatening hyper | Infection, surgery, abrupt antithyroid stop |
| Myxedema coma | Life-threatening hypo | Infection, cold exposure, missed levothyroxine |
Feedback: primary hypo → high TSH, low free T4; primary hyper → low TSH, high free T4/T3.
2. Causes and Risk Factors
- Autoimmune disease, female sex, family history, pregnancy/postpartum, aging
- Neck radiation, iodine excess/deficiency, amiodarone, contrast, pituitary disease (secondary disorders)
3. Signs and Symptoms
Hypo: fatigue, weight gain, cold intolerance, constipation, bradycardia, dry skin, hair loss, depression, menorrhagia, periorbital edema, delayed reflexes. Severe: myxedema, hypothermia, hypoventilation, hyponatremia, coma.
Hyper: weight loss, heat intolerance, diarrhea, tachycardia/AF, tremor, anxiety, insomnia, warm moist skin, lid lag; Graves → exophthalmos, pretibial myxedema. Storm: fever, severe tachycardia, delirium, vomiting, shock.
4. Diagnostics and Labs
Lab reference ranges vary by laboratory. Always use your facility’s ranges.
| Test | Typical adult range (approx.) | Nursing relevance |
|---|---|---|
| TSH | ~0.4–4.5 mU/L | First-line screen |
| Free T4 | Lab-dependent (~0.8–1.8 ng/dL) | Confirms direction of disorder |
| Free T3 / total T3 | Lab-dependent | Sometimes elevated first in hyper |
| TPO / TSI antibodies | — | Hashimoto vs Graves support |
| Radioactive iodine uptake | — | Cause differentiation |
| Calcium / PTH postop | Watch hypocalcemia | Parathyroid risk after thyroidectomy |
| ECG | — | AF in hyperthyroidism |
5. Priority Nursing Assessments
- VS (HR, temp), rhythm, weight trends
- Neuro/mental status; eye symptoms (Graves)
- Airway after thyroidectomy; dressing; bleeding behind the neck
- Hypocalcemia signs postop (tingling, Chvostek/Trousseau, laryngospasm)
- Medication timing adherence; interactions (binding agents vs levothyroxine)
- Cool/warm environment needs
6. Priority Nursing Interventions
- Hypo: warming, gentle activity, fiber/fluids for constipation, skin care; myxedema → airway, IV thyroid hormone as ordered, glucose, steroids if concurrent adrenal issue suspected
- Hyper: calm cool room, high-calorie diet as ordered, eye protection for exophthalmos, telemetry
- Storm: continuous monitoring, cooling (avoid shivering), O₂, IV fluids, antithyroid drugs, iodine after antithyroid per protocol, beta blockers, treat trigger
- Thyroidectomy: semi-Fowler, support head, tracheostomy tray/ calcium gluconate available per protocol, voice checks, monitor drain/dressing
7. Medications
| Class / examples | Role | Nursing considerations |
|---|---|---|
| Levothyroxine | Hypothyroid replacement | Morning empty stomach; lifelong; don’t switch brands casually; watch for hyper symptoms if over-replaced |
| Methimazole | Blocks hormone synthesis | Agranulocytosis (fever/sore throat → hold & report); prefer non-1st trimester pregnancy considerations |
| PTU | Blocks synthesis + peripheral conversion | Hepatotoxicity; used selectively (e.g., 1st trimester/storm protocols) |
| Beta blockers (propranolol) | Symptom control | Rate and tremor relief; doesn’t fix hormone production alone |
| Radioactive iodine (I-131) | Ablation | Radiation precautions teaching; later hypothyroidism expected |
| Iodine solutions (SSKI/Lugol) | Decrease vascularity / release | Give after antithyroid agent in storm pathways |
| Calcium / vitamin D | Postop hypoparathyroidism | Monitor ionized Ca²⁺ |
8. Patient Education
- Levothyroxine: same time daily, empty stomach, separate from calcium/iron/antacids by hours
- Report palpitations, insomnia, or chest pain (over-replacement)
- Antithyroid: report fever, sore throat, jaundice
- RAI: avoid close contact with pregnant people/children for instructed period; hydration
- Eye care for Graves; elevate HOB; sunglasses
- MedicAlert; don’t stop meds abruptly
9. Complications
- Thyroid storm; myxedema coma
- AF, high-output HF, osteoporosis (hyper)
- Postop: hemorrhage, airway obstruction, laryngeal nerve injury (hoarseness), hypocalcemia
- Agranulocytosis / hepatotoxicity from antithyroid drugs
10. Memory Aids
- “Hypo = slow & cold; hyper = fast & hot”
- “Check behind the neck” after thyroidectomy
- “Tingling lips/fingers postop → calcium”
- “Levothyroxine: AM, empty stomach”
- “Fever + sore throat on methimazole → call now”
11. NCLEX-Style Practice Questions
1. Priority assessment in the first hours after thyroidectomy?
A. Ambulation distance
B. Airway patency, bleeding (including posterior neck), and voice/calcium signs
C. Teaching about RAI only
D. Starting a high-fiber diet immediately
Answer: B. Airway compromise and bleeding are immediate threats; hypocalcemia can appear as neuromuscular irritability.
2. Which labs fit primary hypothyroidism?
A. Low TSH, high free T4
B. High TSH, low free T4
C. High TSH, high free T4
D. Low TSH, low free T4 only from pituitary failure always labeled primary
Answer: B. Primary gland failure raises TSH while free T4 falls.
3. Client on methimazole reports fever and sore throat. Best action?
A. Encourage gargles and continue med
B. Hold the drug and notify provider—possible agranulocytosis; anticipate CBC
C. Double the next dose
D. Switch to aspirin only
Answer: B. Agranulocytosis is a dangerous adverse effect.
4. Levothyroxine teaching that shows understanding?
A. “I’ll take it with my calcium chew at breakfast.”
B. “I’ll take it on an empty stomach in the morning and space it from calcium/iron.”
C. “I’ll stop it when I feel better.”
D. “I only need it during winter.”
Answer: B. Absorption matters; therapy is usually lifelong for primary hypo.
5. Which finding is most consistent with thyroid storm?
A. Bradycardia and hypothermia
B. High fever, severe tachycardia, and altered mentation
C. Isolated constipation
D. Weight gain of 2 lb
Answer: B. Storm is an extreme hypermetabolic emergency.
References
MedlinePlus. (n.d.). Hypothyroidism. National Library of Medicine. Retrieved October 15, 2026, from https://medlineplus.gov/hypothyroidism.html
MedlinePlus. (n.d.). Hyperthyroidism. National Library of Medicine. Retrieved October 15, 2026, from https://medlineplus.gov/hyperthyroidism.html
National Council of State Boards of Nursing. (2026). 2026 NCLEX-RN test plan. https://www.nclex.com/test-plans.page
Armstrong, M., Asuka, E., & Fingeret, A. (2023). Physiology, thyroid function. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK537039/
Idrose, A. M. (2023). Thyroid storm. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK448095/