ABSTRACT
Introduction 384
Hyperthyroidism 384
Hypothyroidism 394
Thyroid disease in pregnancy 396
Thyroid enlargement 396
Conclusion 400
Deficiencies in current knowledge and directions for
future research 401
Key evidence 401
Key learning points 401
References 401
Diagnosis precedes treatment
Rusell John Howard, 1875-1942
Benign thyroid disease is common with thyroid dysfunction affecting around 2 per cent of women and 0.2 per cent of men in the UK. Hyperthyroidism is a pathological syndrome in which tissue is exposed to excessive amounts of circulating thyroid hormone, leading to a clinical picture of thyrotoxicosis. Hypothyroidism results from insufficient production and secretion of thyroid hormones. Our understanding of the effects of thyroid hormones under physiological circumstances, as well as in pathological conditions, has increased dramatically over the last two centuries and it has become clear that overt thyroid dysfunction is associated with significant morbidity and mortality. Although the evidence suggests that successful treatment of overt thyroid dysfunction significantly improves overall survival, the issue of treating mild or subclinical hypo-and hyperthyroidism remains controversial. In addition to thyroid dysfunction, enlargement of the thyroid gland affects up to 60 per cent of the population, with higher frequencies in women and the elderly. Most patients with thyroid enlargement can be managed conservatively after malignancy is ruled out, the challenge to the clinician being to identify the minority of patients with thyroid cancer who therefore require surgical intervention and additional therapies.
