Overview
Hyperthyroidism
1. Clinical Overview
Summary
Hyperthyroidism is excess thyroid hormone causing hypermetabolic state. The most common cause is Graves' disease (autoimmune, TSH receptor antibodies). Other causes include toxic multinodular goitre and toxic adenoma. Diagnosis is with suppressed TSH and elevated free T4/T3. Treatment options include antithyroid drugs (carbimazole), radioiodine, and surgery. Graves' ophthalmopathy requires specialist management. Thyroid storm is a life-threatening emergency.
Key Facts
- Definition: Excess thyroid hormone production
- Most common cause: Graves' disease (70-80%)
- Lab findings: TSH low, fT4/fT3 elevated
- First-line treatment: Carbimazole (block-and-replace or titration)
Clinical Pearls
Graves' Triad: Diffuse goitre + ophthalmopathy + dermopathy = Graves'.
Carbimazole Warning: Risk of agranulocytosis - warn about sore throat/fever.
2. Causes
| Cause | Features |
|---|---|
| Graves' disease | Diffuse goitre, ophthalmopathy, TRAb positive |
| Toxic multinodular goitre | Elderly, nodular goitre |
| Toxic adenoma | Single hot nodule |
| Thyroiditis | Transient, painful (subacute) or silent |
| Drug-induced | Amiodarone, iodine |
3. Management
Antithyroid Drugs
| Drug | Dose | Notes |
|---|---|---|
| Carbimazole | 20-40mg/day then titrate | Block-and-replace or dose titration |
| Propylthiouracil | Alternative | Preferred in 1st trimester pregnancy |
Treat for 12-18 months (Graves'); remission 50%.
Other Options
- Radioiodine (definitive; hypothyroidism common)
- Surgery (thyroidectomy - large goitre, compression, cosmetic)
Beta-Blockers
- For symptom control (propranolol 40-80mg TDS)
4. References
- Ross DS et al. 2016 ATA Guidelines for Hyperthyroidism. Thyroid. 2016;26(10):1343-1421. PMID: 27521067
Last Reviewed: 2026-01-01 | MedVellum Editorial Team