Deficiency
Thyroid-stimulating hormone (TSH)
Adrenocorticotropic hormone (ACTH)
mild hyponatremia (mild inappropriate ADH syndrome owing to the normal inhibitory effect of T3 on ADH). The TRH stimulation test distinguishes an anterior pituitary from a hypothalamic disorder.
Low ACTH; low cortisol; fasting hypoglycemia (cortisol is gluconeogenic); mild hyponatremia (mild inappropriate ADH syndrome owing to the inhibitory effect of cortisol on ADH; normal potassium, since ACTH does not affect mineralocorticoid production in th
Low prolactin. No prolactin response with TRH stimulation test.