[Subclinical hypothyroidism--does it have to be treated?].

Every comprehensive laboratory evaluation should include measurement of the TSH level, since even subclinical hypothyroidism may have a negative impact on the organism. In 95% of all persons with a healthy thyroid, the TSH is between 0.4 and 2.5 microU/ml. If the value exceeds the latter figure, autoimmune thyroiditis as the cause of the subclinical hyperthyroidism must be excluded. Consideration must, however, be given to the fact that severe general diseases, as well as various medications, may have an unspecific influence on the TSH value. Subclinical hypothyroidism is associated with changes in the cholesterol level, cardiovascular effects and neuromuscular symptoms. Short-term studies have demonstrated a positive effect on these symptoms for early replacement treatment with L-thyroxine.