Should I treat a raised thyroid stimulating hormone (at levels below 10mIU/L and borderline T4 when there are symptoms?
Does the presence of thyroid antibodies influence the treatment decision? A raised TSH (but below 10mIU/L) and free T4 (FT4) within the normal range define subclinical hypothyroidism. This is relatively common (prevalence 1 to 10%), affecting women more, with rates of progression to overt hypothyroidism raging from 3 to 20%. Those at highest risk of eventually becoming hypothyroid are those with goitre and/or elevated antithyroid antibodies. A similar biochemical picture is also seen in the sick euthyroid syndrome, and thyroid function tests need to be repeated six to eight weeks after recovery from an acute illness. An important cause of an elevated TSH that should also be considered is untreated adrenal insufficiency (Addison’s disease) since treatment with thyroxine can potentially trigger an Addisonian crisis. Usually, subclinical hypothyroidism is picked up incidentally in asymptomatic patients. In symptomatic patients, symptoms related to hypothyroidism tend to be non-specific an
