LAUSR

### What you need to know A 36 year old woman presents to her GP with a six week history of palpitations, agitation, and unintentional weight loss of 12 kg over four months. She initially attributed her symptoms to stress relating to work pressures and a recent house move. Blood tests are arranged, which show a fully suppressed thyroid stimulating hormone (TSH) of <0.01 mU/L and free thyroxine of 86.1 pmol/L. Hyperthyroidism describes excess hormone production from the thyroid gland. Thyrotoxicosis is the clinical state arising from excess circulating thyroid hormones due to any cause, including hyperthyroidism (fig 1). Fig 1 Causes of thyrotoxicosis. Common causes are listed in bold Hyperthyroidism is a biochemical diagnosis. Establishing the underlying aetiology is essential to determine appropriate management. Overall population prevalence of hyperthyroidism is 0.3%-2% and annual incidence is 0.1-4 per 1000.12 Graves’ disease accounts for up to 80% of cases, with peak incidence at age 30-50 (F:M 10:1). In older adults, toxic adenoma/multinodular goitre are responsible for a higher proportion of cases. This article describes the first reasonable steps in diagnosing and managing hyperthyroidism for non-specialists in primary care.