[The practice guideline 'Thyroid disorders' (first revision) from the Dutch College of General Practitioners; a response from the perspective of internal medicine].

The revised practice guideline from the Dutch College of General Practitioners offers straightforward instruction on the diagnosis and treatment of thyroid dysfunction. Most cases of hypothyroidism can indeed be managed by general practitioners, and indications for referral to specialists are made clear. For substitution therapy with levothyroxine in otherwise healthy subjects the guidelines advocate the 'start low, go slow'-principle under the adage 'better safe than sorry'. The guidelines recommend referral of thyrotoxic patients to an internist for treatment, unless the general practitioner has sufficient expertise in this area. Self-limiting thyrotoxicosis (e.g. subacute and postpartum thyroiditis), however, can generally be managed in a primary care setting. The guidelines recommend no intervention for subclinical thyroid dysfunction. Most internists believe that treatment is warranted for subclinical hyperthyroidism in patients with a multinodular goitre, especially in postmenopausal women. Assessment of thyroid peroxidase antibodies is not mentioned in the guidelines, but this may help inform treatment decisions, especially in patients with subclinical hypothyroidism and pregnant women. The recommendation to request thyroid ultrasound for patients with a solitary thyroid nodule or a dominant nodule in a multinodular goitre before referral seems superfluous, since specialists are also likely to request an ultrasound in these patients for the purpose of guiding fine-needle aspiration therapy.