Long-term follow-up of primary hyperthyroidism

In a patient who achieved remission of Graves disease with antithyroid drug therapy, long-term euthyroidism cannot be guaranteed. Relapse can occur despite completing the recommended 12- to 18-month course of therapy, including in patients whose thyroid stimulating hormone (TSH)-receptor antibody concentration normalised before treatment was stopped. Hypothyroidism can also occur following remission, including many decades later. Following remission of hyperthyroidism, clinical and biochemical follow-up is recommended every 3 to 4 months for the first year, then annually for 5 years. Counsel the patient to seek prompt assessment if any symptoms of recurrent hyperthyroidism, or of hypothyroidism, develop.

Thyroidectomy is followed by permanent hypothyroidism, and radioiodine is likely to be followed eventually by hypothyroidism. Subsequent lifelong thyroxine replacement is usually required. See Thyroxine replacement in adults for management.

If long-term maintenance therapy with an antithyroid drug is used, review thyroid function every 3 months initially. Once the patient is stable and euthyroid, the review interval can be extended to 6-monthly.

Women with prior or current Graves disease who become pregnant require specific monitoring during pregnancy. Their infants have a low risk of developing neonatal hyperthyroidism. Thyroidectomy or radioiodine before pregnancy does not eliminate this risk. See Neonatal hyperthyroidism.