Hypopituitarism is present in 75% to 80% of patients with ONH. The anterior pituitary gland contributes to growth, metabolism, and sexual development. The most common pituitary endocrinopathies are growth hormone (GH) deficiency (70%), hypothyroidism (43%), adrenal insufficiency (27%), and diabetes insipidus (5%). Absence of GH may often be indicated by short stature, although this is not always the case. Other indicators of GH deficiency may include hypoglycemic events (including seizures), prolonged jaundice, micropenis in boys, and delayed dentition. Testing for GH may involve blood tests (IGF-1 and IGFBP-3), growth hormone stimulation test, or bone age x-ray of the hand or wrist (or body for children younger than 2 years). A poorly functioning pituitary gland may also cause a lack of thyroid hormone, leading to central hypothyroidism. Thyroid hormone is critical for growth and brain development, especially during the first few weeks to months of life. Children with untreated hypothyroidism are at high risk of mental retardation; thus, early detection is crucial. Central hypothyroidism can be diagnosed by a low or normal thyroid-stimulating hormone (TSH) in the presence of a low level of free T4. Free T-4 should be checked annually for at least four years. Cortisol is made in times of stress. Approximately one-quarter of patients with ONH have adrenal insufficiency, meaning they do not produce enough cortisol on a daily basis or in stressful situations. Imbalances in sex hormone may result in a delay in sexual development (puberty) or precocious puberty. Sex hormones may be tested from birth to 6 months of age (during a mini-puberty). Hyperprolactinemia (an excess of prolactin) often occurs in conjunction with ONH and indicates either dysfunction of the hypothalamus or a disconnect between the hypothalamus and pituitary gland. Hyperprolactinemia often correlates with development of obesity in children with ONH. The posterior pituitary gland produces anti-diuretic hormone (ADH), which controls outflow of water from the body by urine. ADH deficiency, also known as diabetes insipidus (DI), results in dehydration and high sodium levels in the body from excessive urination. Testing for DI involves blood and urine testing, including water deprivation tests, to determine ADH creation levels by the body. DI may be treated with a medication called desmopressin acetate (DDAVP). Oxytocin is also produced in the posterior pituitary gland. Though best known for its role in childbirth and lactation, oxytocin has also been found to have a role in human bonding, increase in trust, and