What criteria should I use to determine when to refer a patient with hyperthyroidism to an endocrinologist?

Refer a patient with hyperthyroidism to an endocrinologist if any of the following criteria are met:

• There is a confirmed diagnosis of overt hyperthyroidism based on thyroid function tests (TFTs) ¹.
• Symptoms suggest a serious complication such as thyrotoxic crisis, requiring emergency admission ¹.
• A pituitary or hypothalamic disorder is suspected, warranting urgent specialist assessment ¹.
• The patient has a goitre, thyroid nodule, or structural thyroid changes, especially if malignancy is suspected; in such cases, refer urgently via a suspected cancer pathway ¹,³.
• The patient is planning a pregnancy, as specialist management may be needed ¹.
• There is troublesome symptomatology despite beta-blocker treatment, or beta-blockers are contraindicated or not tolerated, prompting consideration of antithyroid drugs under specialist advice ¹.
• The patient is at risk of complications from hyperthyroidism or is on drugs such as amiodarone or lithium that affect thyroid function, requiring liaison with endocrinology ¹.
• Subclinical hyperthyroidism is persistent with TSH <0.1 mIU/L on at least two occasions three months apart, with evidence of thyroid disease or symptoms of thyrotoxicosis, especially in adults over 65, postmenopausal women not on oestrogens or bisphosphonates, or those with cardiac risk factors, heart disease, or osteoporosis ¹,³.
• In children and young people with subclinical hyperthyroidism, specialist advice should be sought regardless of severity ³.

While awaiting specialist assessment, consider beta-blocker therapy for symptom control in adults without contraindications and seek specialist advice before starting antithyroid drugs in primary care ¹.