2006 ICD-9-CM Volume 1 Diagnosis Codes Home > Endocrine, Nutritional And Metabolic Diseases, And Immunity Disorders 240-279 > Disorders Of Thyroid Gland 240-246 > ICD-9-CM Diagnosis 243 Congenital hypothyroidism A condition due to congenital lack of thyroid hormone, marked by arrested physical and mental development, dystrophy of the bones and soft parts, and lowered basal metabolism. It is the congenital form of thyroid deficiency, while MYXEDEMA is the acquired form. 243 is a specific code that can be used to specify a diagnosis 243 contains 21 index entries