Subclinical hypothyroidism: When to treat

Abstract

Subclinical hypothyroidism (SCH)is a conditionin which
there i s a per s i s tent elevation in thy roidstimulatinghormone (TSH) (12 weeks or longer) in the
setting of FT4/T4concentrations that are repeatedly
1
found within the referenceinterval. Subclinical hypot
hyroidism may be categorized as grade 1 when TSH
level sare between the upper limit of the reference range
and 9.9mIU/L and as grade 2 if serum TSH levels
are10mIU/L or higher.As multiple factors, such as
subacute thyroiditis,recovery from nonthyroidal illness,
andmedication (e.g., amiodarone and lithium),
cancause transient abnormalities in the serum TSH
level,subclinical hypothyroidism is diagnosed after
2
excluding all other causes of elevated TSH levels.