The prevalence of hypothyroidism in the UK is 2%. It is 10 times more common in women, with incidence figures of 4.1/1000 women/year and 0.8/1000 men/year. Thyrotoxicosis is much less common, with a prevalence of 0.4%. It is also more common in women (0.77/1000 women/year versus 0.14/1000 men/year). The standard investigation if either disease is suspected is blood thyroid stimulating hormone (TSH).
Guidance from the British Thyroid Association (2006) states that TSH should be tested if thyrotoxicosis is suspected, with a normal TSH …