Labels:text | screenshot | black | black and white | document | monochrome OCR: uitary will help The correlation between levels of the hormone and the target organ hormon a target to establish the cause of underactivity i with gland (Fig. 2.21); for example, in a patie el hypothyroidism, low or normal TSH le tary gland combined with low T4 levels imply pit . High malfunction or pituitary hypothyroidis T4 level TSH concentrations combined with a lo f (that is, indicate disease in the thyroid gland its primary hypothyroidism).