The symptoms due to a prolactinoma are broadly divided into those that are caused by increased prolactin levels or mass effect.

Those that are caused by increased prolactin levels are:

- Amenorrhea (disappearance of ovulation periods)

- Galactorrhea (Milk production; infrequent in men)

- Loss of axillary and pubic hair

- Hypogonadism (Reduced function of the gonads.)

- Gynecomastia (an increase in male breast size)

- Erectile dysfunction (in males)

Those that are caused by mass effect are:

- Bitemporal hemianopsia (due to pressure on the optic chiasm)

- Vertigo

- Nausea, vomiting

A prolactinoma is a benign tumor (adenoma) of the pituitary gland that produces a hormone called prolactin. It is the most common type of functioning pituitary tumor. Symptoms of prolactinoma are too much prolactin in the blood (hyperprolactinemia), or those caused by pressure of the tumor on surrounding tissues.

Prolactin stimulates the breast to produce milk, and has many other functions such as regulation of mood. Hence prolactin levels are usually higher during pregnancy and after childbirth. After delivery of a baby, a mother's prolactin levels come down to normal a few weeks after breastfeeding is discontinued. Each time the milk is dispensed, prolactin levels rise; this process may cycle to maintain milk production. In males it is responsible for the sexual refractory period after orgasm and excess levels can lead to erectile dysfunction.

Based on size, a prolactinoma can be classified as a "microprolactinoma" (10 mm diameter).

In women, a high blood level of prolactin often causes hypoestrogenism with anovulatory infertility and a decrease in menstruation. In some women, menstruation may disappear altogether (amenorrhoea). In others, menstruation may become irregular or menstrual flow may change. Women who are not pregnant or nursing may begin producing breast milk. Some women may experience a loss of libido (interest in sex) and breast pain, especially when prolactin levels begin to rise for the first time, as the hormone promotes tissue changes in the breast. Intercourse may become difficult or painful because of vaginal dryness.

In men, the most common symptoms of hyperprolactinaemia are decreased libido, sexual dysfunction (in both men and women), erectile dysfunction, infertility, and gynecomastia. Because men have no reliable indicator such as menstruation to signal a problem, many men with hyperprolactinaemia being caused by a pituitary adenoma may delay going to the doctor until they have headaches or eye problems caused by the enlarged pituitary pressing against the adjacent optic chiasm. They may not recognize a gradual loss of sexual function or libido. Only after treatment do some men realize they had a problem with sexual function.

Because of hypoestrogenism and hypoandrogenism, hyperprolactinaemia can lead to osteoporosis.

Galactorrhea hyperprolactinemia is increased blood prolactin levels associated with galactorrhea (abnormal milk secretion). It may be caused by such things as certain medications, pituitary disorders and thyroid disorders. The condition can occur in males as well as females. Relatively common etiologies include prolactinoma, medication effect, kidney failure, granulomatous diseases of the pituitary gland, and disorders which interfere with the hypothalamic inhibition of prolactin release. Ectopic (non-pituitary) production of prolactin may also occur. Galactorrhea hyperprolactinemia is listed as a “rare disease” by the Office of Rare Diseases of the National Institutes of Health. This means that it affects less than 200,000 people in the United States population.

Hyperprolactinaemia may be caused by either disinhibition (e.g., compression of the pituitary stalk or reduced dopamine levels) or excess production from a prolactinoma (a type of pituitary adenoma). A blood serum prolactin level of 1000–5000 mIU/L could be from either mechanism, but >5000 mIU/L (>200 µg/L) is likely due to the activity of an adenoma; macroadenomas (large tumours over 10 mm diameter) have levels of prolactin up to 100,000 mIU/L.

Hyperprolactinemia inhibits the secretion of gonadotropin-releasing hormone (GnRH) from the hypothalamus (by increasing the release of dopamine from the arcuate nucleus), which in turn inhibits the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary gland and results in diminished gonadal sex hormone production (termed hypogonadism). This is the cause of many of the symptoms described below.

In many people, elevated prolactin levels remain unexplained and may represent a form of hypothalamic–pituitary–adrenal axis dysregulation.

Symptoms caused by hormone excess and associated mass effects include:

Symptoms of galactorrhea hyperprolactinemia include a high blood prolactin level, abnormal milk production in the breast, galactorrhea, menstrual abnormalities, reduced libido, reduced fertility, puberty problems, and headaches.

For the diagnosis of hyperpituitarism it depends on the cell type(s) affected, clinical manifestations of hormone excess may include, gigantism or acromegaly, which can be identified by clinical and radiographic results. Cushing's disease diagnosis is done with a physical examination, laboratory tests and X rays of the pituitary glands (to locate tumors) For prolactinoma, diagnosis comes in the form of the measurement of serum prolactin levels and x-ray of pituitary gland.

One particular familial form is associated with sensorineural deafness (Pendred's syndrome).

OMIM includes the following:

Hyperthyroxinemia or hyperthyroxinaemia is a thyroid disease where the serum levels of thyroxine are higher than expected.

The term is sometimes used to refer to hyperthyroidism, but hyperthyroidism is a more general term.

Types include:

- Familial dysalbuminemic hyperthyroxinemia

- Familial euthyroid hyperthyroxinemia

- Thyroid hormone resistance syndrome

Thyroid dyshormonogenesis (or dyshormogenetic goiter) is a rare condition due to genetic defects in the synthesis of thyroid hormones.

Patients develop hypothyroidism with a goitre.either deficiency of thyroid enzymes or inability to concentrate or ineffective binding

Familial male-limited precocious puberty, often abbreviated as FMPP, also known as familial sexual precocity or gonadotropin-independent testotoxicosis, is a form of gonadotropin-independent precocious puberty in which boys experience early onset and progression of puberty. Signs of puberty can develop as early as an age of 1 year.

The spinal length in boys may be short due to a rapid advance in epiphyseal maturation. It is an autosomal dominant condition with a mutation of the luteinizing hormone (LH) receptor. Treatment is with drugs that suppress gonadal steroidogenesis, such as cyproterone acetate, ketoconazole, spironolactone, and testolactone. Alternatively, the combination of the androgen receptor antagonist bicalutamide and the aromatase inhibitor anastrozole may be used.

Pickardt's syndrome may cause difficulties in differential diagnosis of pituitary adenomas, as both suprasellar hormone-inactive adenomas and prolactinomas may be associated with increased prolactin levels, central hypgogonadism and central hypothyroidism. Usually, the prolactin levels are higher in case of a true prolactinoma, but the concentration ranges overlap.

MEN2 can present with a sign or symptom related to a tumor or, in the case of multiple endocrine neoplasia type 2b, with characteristic musculoskeletal and/or lip and/or gastrointestinal findings.Medullary thyroid carcinoma (MTC) represent the most frequent initial diagnosis. Occasionally pheochromocytoma or primary hyperparathyroidism may be the initial diagnosis.

Pheochromocytoma occurs in 33-50% of MEN2 cases. In MEN2A, primary hyperparathyroidism occurs in 10–50% of cases and is usually diagnosed after the third decade of life. Rarely, it may present in childhood or be the sole clinical manifestation of this syndrome.

MEN2A associates medullary thyroid carcinoma with pheochromocytoma in about 20–50% of cases and with primary hyperparathyroidism in 5–20% of cases.MEN2B associates medullary thyroid carcinoma with pheochromocytoma in 50% of cases, with marfanoid habitus and with mucosal and digestive neurofibromatosis.

In familial isolated medullary thyroid carcinoma the other components of the disease are absent.

In a review of 85 patients 70 had Men2A and 15 had Men2B. The initial manifestation of MEN2 was medullary thyroid carcinoma in 60% of patients, medullary thyroid carcinoma synchronous with pheochromocytoma in 34% and pheochromocytoma alone in 6%. 72% had bilateral pheochromocytomas.

Typical manifestations of Pickardt–Fahlbusch syndrome are hypothyroidism with reduced TSH values and functional hyperprolactinemia (which is caused by disinhibition of prolactin release). Other endocrine disorders that are usually associated with Pickardt syndrome are suprasellar failures like secondary hypogonadism, reduced levels of growth hormone and, in more severe cases, secondary adrenal insufficiency.

An adenoma of a parathyroid gland may secrete inappropriately high amounts of parathyroid hormone and thereby cause primary hyperparathyroidism.

Multiple endocrine neoplasia type 2 (MEN2) (also known as "Pheochromocytoma and amyloid producing medullary thyroid carcinoma", "PTC syndrome," and "Sipple syndrome") is a group of medical disorders associated with tumors of the endocrine system. The tumors may be benign or malignant (cancer). They generally occur in endocrine organs (e.g. thyroid, parathyroid, and adrenals), but may also occur in endocrine tissues of organs not classically thought of as endocrine.

MEN2 is a sub-type of MEN (multiple endocrine neoplasia) and itself has sub-types, as discussed below.

Pituitary adenomas are seen in 10% of neurological patients. A lot of them remain undiagnosed. Treatment is usually surgical, to which patients generally respond well. The most common subtype, prolactinoma, is seen more often in women, and is frequently diagnosed during pregnancy as the hormone progesterone increases its growth. Medical therapy with cabergoline or bromocriptine generally suppresses prolactinomas; progesterone antagonist therapy has not proven to be successful.

Central diabetes insipidus, also called neurogenic diabetes insipidus, is a type of diabetes insipidus due to a lack of vasopressin (ADH) production in the brain. Vasopressin acts to increase the volume of blood (intravascularly), and decrease the volume of urine produced. Therefore, a lack of it causes increased urine production and volume depletion.

It is also known as neurohypophyseal diabetes insipidus, referring to the posterior pituitary (neurohypophysis), which is supplied by the hypothalamus in the brain. This condition has only polyuria in common with diabetes and although not mutually exclusive, with most typical cases, the name diabetes insipidus is a misleading misnomer. A better name might be "hypothalamic-neurohypophyseal ADH deficiency".

The lack of vasopressin production usually results from some sort of damage to the pituitary gland. It may be caused due to damage to the brain caused by:

- Benign suprasellar tumors (20% of cases)

- Infections (encephalitis, tuberculosis etc.)

- Trauma (17% of cases) or neurosurgery (9% of cases)

- Non-infectious granuloma (sarcoidosis, Langerhans cell histiocytosis etc.)

- Leukaemia

- Autoimmune - associated with thyroiditis

- Other rare causes which include hemochromatosis and histiocytosis.

Vasopressin is released by the posterior pituitary, but unlike most other pituitary hormones, vasopressin is produced in the hypothalamus. Neurogenic diabetes insipidus can be a failure of production at the hypothalamus, or a failure of release at the pituitary.

Familial hyperaldosteronism is a group of inherited conditions in which the adrenal glands, which are small glands located on top of each kidney, produce too much of the hormone aldosterone. Excess aldosterone causes the kidneys to retain more salt than normal, which in turn increases the body's fluid levels and causes high blood pressure. People with familial hyperaldosteronism may develop severe high blood pressure, often early in life. Without treatment, hypertension increases the risk of strokes, heart attacks, and kidney failure. There are other forms of hyperaldosteronism that are not inherited.

Familial hyperaldosteronism is categorized into three types, distinguished by their clinical features and genetic causes. In familial hyperaldosteronism type I, hypertension generally appears in childhood to early adulthood and can range from mild to severe. This type can be treated with steroid medications called glucocorticoids, so it is also known as glucocorticoid-remediable aldosteronism (GRA). In familial hyperaldosteronism type II, hypertension usually appears in early to middle adulthood and does not improve with glucocorticoid treatment. In most individuals with familial hyperaldosteronism type III, the adrenal glands are enlarged up to six times their normal size. These affected individuals have severe hypertension that starts in childhood. The hypertension is difficult to treat and often results in damage to organs such as the heart and kidneys. Rarely, individuals with type III have milder symptoms with treatable hypertension and no adrenal gland enlargement.

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. The various types of familial hyperaldosteronism have different genetic causes.

It is unclear how common these diseases are. All together they appear to make up less than 1% of cases of hyperaldosteronism.

Children with constitutional delay of growth and puberty (CDGP), the most common cause of short stature and pubertal delay in males, typically have slowed linear growth within the first 3 years of life. In this variant of normal growth, linear growth velocity and weight gain slows beginning as young as age 3–6 months, resulting in downward crossing of growth percentiles, which often continues until age 2–3 years. At that time, growth resumes at a normal rate, and these children grow either along the lower growth percentiles or beneath the curve but parallel to it for the remainder of the prepubertal years.

At the expected time of puberty, the height of children with CDGP begins to drift further from the growth curve because of delay in the onset of the pubertal growth spurt. Catch-up growth, onset of puberty, and pubertal growth spurt occur later than average, resulting in normal adult stature and sexual development. Although CDGP is a variant of normal growth rather than a disorder, delays in growth and sexual development may contribute to psychological difficulties, warranting treatment for some individuals. Recent studies have suggested that referral bias is largely responsible for the impression that normal short stature per se is a cause of psycho-social problems; non-referred children with short stature do not differ from those with more normal stature in school performance or socialization.

Familial hypocalciuric hypercalcemia (FHH) is a condition that can cause hypercalcemia, a serum calcium level typically above 10.2 mg/dL. It is also known as familial benign hypocalciuric hypercalcemia (FBHH) where there is usually a family history of hypercalcemia which is mild, a urine calcium to creatinine ratio <0.01, and urine calcium <200 mg/day.

Most cases of familial hypocalciuric hypercalcemia are asymptomatic. Laboratory signs of FHH include:

- Hypercalcemia

- Hypocalciuria ( Ca excretion rate < 0.02 mmol/L)

- Hypermagnesemia

- High normal to mildly elevated parathyroid hormone

Constitutional delay of growth and puberty (CDGP) is a term describing a temporary delay in the skeletal growth and thus height of a child with no physical abnormalities causing the delay. Short stature may be the result of a growth pattern inherited from a parent (familial) or occur for no apparent reason (idiopathic). Typically at some point during childhood, growth slows down, eventually resuming at a normal rate. CDGP is the most common cause of short stature and delayed puberty.