Some 12 years ago a 56-year-old man was observed for Epipharyngitis. All the tests, including cytology of the epipharynx, were normal. Thyroid tests, including free thyroxine and triiodthyronine, were normal, only the hypophysial thyroid stimulating hormone was elevated. In a second IGR TSH test it was again elevated. The patient was seen again: he was adynamic. Thyroxine was prescribed in a small initial dose of 25 mgr. daily and after several weeks he was consuming 125 mgr thyroxine daily. TSH was normalised. This inapparent expression of primary hypothyreosis with elevated TSH only was the trigger for many cases of hyporthyreosis without laboratory or clinical signs of thyroid hypofunction. In this paper 27 cases are presented with the sign of elevated TSH only.