thyroid function test1

Thyroid disease is common (approximately 1% of the population), presents with wide ranging and often nonspecific symptoms - so needs to be considered in many differentials and, once diagnosed, needs to be regularly monitored to optimise therapy. As a consequence, thyroid function tests (TFTs) are the most commonly used endocrine test - 10 million TFTs are ordered annually in the UK, at a cost of over £30 million. Dissenters point out that TFTs are widely used in patients with a low pretest probability of thyroid disease and have a low yield consequently.In General Practice, the most common use of a TFT is as part of a screen for nonspecific fatigue or illness. The value of such tests without a goitre or other clinical features has been challenged and some advocate the use of watchful waiting with the delayed use of laboratory tests (at 4 weeks post presentation) as a more appropriate strategy for investigating unexplained fatigue. Similarly the value of performing TFTs on obese patients without any other symptoms suggestive of hypothyroidism is doubtful.