<unk>  is referred to the deficiency of one of the pituitary gland hormones or more while the deficiency of all pituitary hormones is known as panhypopituitarism. A study comprising two cross-sectional surveys showed the prevalence of<unk>  to be 29 per 100,000 individual in the first survey and 45.5 per 100,000 individual in the second survey.<unk>  can be classified on the basis of the anatomical location of pathology into primary (pituitary) and secondary (hypothalamic)<unk> . It can also be classified on the basis of the portion of gland involvement into partial or complete glandular involvement. The pathophysiology of<unk>  mainly involves ischemic injury of the pituitary gland. The ischemia may be due to hemorrhage, tumors, brain injury, and compression or occlusion of the hypophyseal blood vessels. Causes of<unk>  may be classified based upon the etiology such as congenital or acquired. Common congenital causes include idiopathic, anatomic lesion in the sella turcica and CNS malformations. Common acquired causes may include pituitary macroadenoma, craniopharyngioma, surgery, radiation, traumatic brain injury, Sheehan's syndrome, apoplexy, SAH, meningitis, hypophysitis, meningioma, lymphoma, hemochromatosis and Wegner's granulomatosis. Less common causes include peri-natal insults, genetic causes, and pituitary hypoplasia or aplasia.<unk>  should be differentiated from other diseases causing panhypopituitarism, hypothyroidism, hypogonadism, ACTH deficiency, GH deficiency, ADH deficiency and high prolactin level. Common risk factors in the development of<unk>  may include pituitary tumor or space occupying lesion, pituitary apoplexy, severe blood loss such as Sheehan's syndrome, pituitary surgery, cranial radiation, genetic defects, hypothalamic disease, immunosuppression, inflammatory processes, pituitary infarction and non-compliance with hormone replacement therapy. Less common risk factors include infiltrative disorders, traumatic brain injury causing skull fractures, ischemic stroke and subarachnoid hemorrhage. Screening of<unk>  has been recommended for the patients with traumatic brain injury and patients with a history of radiation exposure on the head. The natural history of<unk>  depends on the severity of damage leading to partial or complete hormonal deficiency. If left untreated can lead to critical consequences.  Complications of<unk>  include adrenal crisis, osteoporosis, electrolyte abnormalities, and diabetes mellitus.<unk>  is often associated with vascular conditions and has a high mortality rate.<unk>  has a good prognosis as long as the hormonal replacement therapy is given adequately. A positive history of head trauma, adenoma, a lesion such as a sellar lesion, or any symptom related to pituitary hormonal deficiency is suggestive of<unk> . Patients of<unk>  may be asymptomatic or show symptoms which can be nonspecific or specific for the deficient hormone. Patients with acute onset of<unk>  can present with a headache, nausea, vomiting, visual impairment, fatigue, cold intolerance, hypotension, and dizziness. Patients with chronic<unk>  can present with pallor, weight loss, and anorexia. Clinical presentation in<unk>  depends upon the onset, the severity of hormonal deficiency and the number of deficient hormones. A subnormal or reduced concentration of pituitary hormones is diagnostic of<unk> . Patients with complete hormonal deficiencies are mostly symptomatic and have low serum concentrations of both, the pituitary hormones as well as the target-organ hormones. Patients having partial hormonal deficiencies are detected by dynamic tests/stimulatory tests such as corticotropin stimulation, insulin-induced hypoglycemia, and metyrapone test. MRI scan with intravenous gadolinium is the imaging procedure of choice in the diagnosis of<unk> . It is preferred over the CT scan as optic chiasm, pituitary stalk, and cavernous sinuses can be seen in MRI. Treatment involves appropriate hormone replacement therapy, which must be taken for the rest of your life that results in significant improvement and reversal of not only the physical symptoms but also the psychological symptoms. Conditions that need a surgical consideration may include pituitary apoplexy , microadenomas with GH or ACTH hypersecretion and debulking macroadenomas with mass symptoms and resistant to medical therapy.<unk>  can be prevented by good obstetric care, minimizing radiation exposure and high-resolution microscopic hypophyseal surgery done by experienced neurosurgeons.
Hypopituitarism
Hyperpituitarism
Constitutional delay of puberty
Hyperprolactinemia
Congenital adrenal hyperplasia
Lipoid congenital adrenal hyperplasia
Multiple endocrine neoplasia
Kallmann syndrome