focused assessment of the patient’s presenting problem Understanding which specific hormone deficits the presenting patient has will help guide further history, physical, and the treatment Cortisol deficiency can present insidiously with fatigue, anorexia, vomiting, and failure to thrive Consider it specifically in patients with unexplained hypoglycemia and/or hyponatremia Of note, hyperkalemia and severe hyponatremia are seen in primary adrenal insufficiency due to an absence of appropriate aldosterone synthesis—this is not related to hypocortisolemia Cortisol deficiency can also present more acutely, as in patients who have fluid and pressor refractory hypotension (see Acute Adrenal Insufficiency section for more information) Patients with thyroid hormone deficiency due to hypopituitarism will often have general complaints of fatigue, cold intolerance, constipation, weight gain, and hair thinning/loss Children often have delayed growth Infants can have hypotonia, hypothermia, and significant constipation (see Congenital Hypothyroidism section) Patients with DI have extreme thirst and polydipsia as well as polyuria Consider in patients who have a history of polydipsia, however, appear volume depleted on examination (see Diabetes Insipidus section) Isolated growth hormone deficiency is most likely to present with poor linear growth, although occasionally an infant or young child will present with hypoglycemia or with microphallus (less than cm, stretched length) In the older child, no specific symptoms or signs indicate a lack of LH and FSH An association between a lack of these hormones and anosmia has been noted (Kallmann syndrome) In the adolescent, a deficiency of LH and FSH may be evidenced as pubertal delay In the neonatal male, hypopituitarism may be accompanied not only by hypoglycemia, but also by microphallus (less than cm, stretched length) This condition illustrates the role of LH and FSH in stimulating testicular function in utero No specific signs or symptoms have been associated with a deficiency of prolactin in childhood Significant liver dysfunction in the neonatal period may be associated with congenital hypopituitarism Hypopituitarism is seen with various midline structural anomalies, including optic nerve hypoplasia, cleft palate, absence of the septum pellucidum, and spina bifida In the older child, intracranial mass lesions, particularly with craniopharyngioma and other pituitary abnormalities, may cause hypopituitarism The presence of visual field abnormalities may aid in localizing the site of the lesion A history of severe head trauma, surgery for CNS tumors, or CNS irradiation should increase the suspicion of hypopituitarism Management/Diagnostic Testing The child with hypopituitarism may require any or all the following therapies Adequate cortisol replacement is an absolute necessity in children with known or suspected secondary adrenal insufficiency (ACTH deficiency) during a time of physiologic stress Cortisol replacement under stress conditions (e.g., trauma, fever, sepsis) should be the equivalent of 50 mg of hydrocortisone/m2/day (hydrocortisone IV infusion 12.5 mg/m2 every hours; hydrocortisone continuous IV infusion at 50 mg/m2/day; cortisone 50 mg/m2 intramuscularly every 24 hours) A child with hypopituitarism presenting in extremis or with severe electrolyte abnormalities should immediately receive an initial rescue dose of hydrocortisone of 50