[Diagnosis of incomplete hypothyroidism]

The clinical picture of mild hypothyroidism consists of mild, often non-specific signs. In general, the diagnosis can only be made in the laboratory. Estimations of protein-bound iodine, thyroxine and tri-iodothyronine in the serum are often within normal limits. A rise in serum TSH and in doubtful cases, the excessive liberation of TSH during the TRH-TSH test confirm the diagnosis. As mild hypothyroidism is often due to auto-immune thyroiditis, the demonstration of anti-thyroid antibodies may guide the clinician.