Excess thyroid hormone synthesis (Graves, toxic nodule) or release (thyroiditis); TSH suppressed with high T3/T4.
History taking
- • Heat intolerance, weight loss with preserved appetite, palpitations, tremor
- • Anxiety, insomnia, frequent stools, oligomenorrhoea
- • Eye symptoms: grittiness, diplopia, proptosis
- • Recent pregnancy/postpartum, iodine exposure, amiodarone
Examination
- • Tachycardia, fine tremor, warm moist skin, lid lag, lid retraction
- • Goitre — diffuse with bruit (Graves) or nodular
- • Proptosis, ophthalmoplegia, pretibial myxoedema
- • Atrial fibrillation, proximal myopathy
Red flags
- • Thyroid storm — fever, tachyarrhythmia, agitation, hyperthermia
- • Atrial fibrillation with rapid ventricular response
- • Severe orbitopathy with vision loss
Differential diagnosis
- • Graves disease, toxic multinodular goitre, toxic adenoma
- • Subacute/silent thyroiditis, postpartum thyroiditis
- • Factitious thyrotoxicosis, struma ovarii
Recommended investigations
- • TSH, free T4, free T3
- • TRAb (TSH receptor antibody) for Graves
- • Radioiodine uptake scan: high in Graves, low in thyroiditis
- • ECG, CBC, LFT before antithyroid drugs
Diagnosis
- • Suppressed TSH with raised free T4/T3 = overt hyperthyroidism
- • Differentiate Graves vs thyroiditis by uptake scan or TRAb
Initial treatment / management
- • Symptomatic: Propranolol 20–40 mg PO QDS
- • Antithyroid drugs: Carbimazole or Methimazole; PTU in first-trimester pregnancy or storm
- • Definitive: radioactive iodine or thyroidectomy
- • Eye care: lubricants, sleep head elevated, urgent referral if vision threatened
Prescription examples
- • Tab Carbimazole 10–20 mg PO TDS initially; titrate to maintenance 5–15 mg/day
- • Tab Propranolol 40 mg PO TDS until euthyroid
- • Counsel about agranulocytosis — stop drug and seek care if fever/sore throat
Follow-up advice
- • Free T4 every 4–6 weeks; TSH lags behind
- • CBC, LFT at baseline; repeat if symptoms
- • Plan definitive therapy after 12–18 months ATD if no remission
Patient counselling
- • Avoid iodinated contrast and seaweed
- • Pregnancy planning — switch to PTU in T1
- • Smoking worsens Graves orbitopathy
Referral criteria
- • Thyroid storm, severe orbitopathy
- • Pregnancy, paediatric thyrotoxicosis
- • Failure of medical therapy / planning RAI or surgery
Clinical pearls
- • Apathetic hyperthyroidism in elderly presents only with AF or weight loss
- • Beta-blockers control symptoms within hours; ATDs take weeks
- • Painful goitre + raised ESR + low uptake = subacute thyroiditis
References
- • ATA Guidelines for Hyperthyroidism and Thyrotoxicosis 2016
- • ETA Guidelines on Graves Orbitopathy 2021
Educational outpatient guide — verify against local guidelines before clinical use.
