Synopsis
Choose safely between medical control, radioiodine and thyroidectomy for hyperthyroidism while anticipating toxicity, relapse, eye disease, fertility implications and peri-operative risk.
- First establish the cause of thyrotoxicosis. Graves' disease, toxic nodular disease and destructive thyroiditis do not share the same response to antithyroid medicines or radioiodine.
- Carbimazole is usual first-line antithyroid treatment for many non-pregnant adults; propylthiouracil is reserved for defined situations because serious hepatic injury is an important risk.
- Before starting an antithyroid medicine, obtain full blood count and liver tests. Routine serial counts do not replace urgent testing when fever, sore throat or mouth ulcers develop.
- Agranulocytosis warning advice must be verbal and written: stop the antithyroid medicine and obtain an urgent neutrophil count rather than taking another dose while awaiting routine review.
- Radioiodine is a definitive option for suitable Graves' or toxic nodular hyperthyroidism, but is contraindicated in pregnancy and breastfeeding and requires local radiation-protection precautions.
- Active thyroid eye disease, immediate pregnancy plans, suspected malignancy, large compressive goitre and inability to follow radiation rules may make radioiodine unsuitable or change preparation.
- Thyroidectomy offers rapid definitive control and tissue diagnosis, especially for large goitre, compression, nodules or selected eye disease, but requires an experienced high-volume team and euthyroid preparation where possible.
- Beta-blockers relieve adrenergic symptoms but do not correct hormone production. Destructive thyroiditis generally needs symptom control rather than carbimazole because synthesis is already low.
- After radioiodine or total thyroidectomy, lifelong biochemical follow-up is required because hypothyroidism is expected or common; a definitive treatment does not mean discharge without replacement planning.
Key red flags
Fever, sore throat, oral ulceration, jaundice, dark urine, severe pruritus or abdominal pain during antithyroid therapy demands urgent assessment. Agranulocytosis and hepatic injury can progress despite an apparently modest dose.
Stridor, positional dyspnoea, dysphagia, venous congestion or vocal change indicates possible compression. Fever, agitation, heart failure and marked tachycardia with thyrotoxicosis indicate a clinical storm pathway rather than routine scoring alone.
Investigation priorities
Confirm biochemical severity and provide a baseline for response.
Management branches
Synthesis-driven Graves' disease or temporary control of nodular hyperthyroidism while definitive care is arranged.
- Confirm cause, obtain baseline blood count and liver tests, review pregnancy possibility and interactions, then select carbimazole or a defined propylthiouracil indication.
- Give written agranulocytosis and hepatic warning advice. Recheck free hormones at the local early interval and adjust by titration or a specialist-agreed block-and-replace plan.
- At the planned course end, assess remission or relapse risk. Recurrent Graves' disease and persistent nodular autonomy prompt shared discussion of further medicine, radioiodine or surgery rather than indefinite drift.