What Is Hypopituitarism?

Rare disorder affecting the pituitary gland has many causes

Table of Contents
View All

Hypopituitarism is a rare disorder that causes the decreased production of one or more of the nine hormones produced by the pituitary gland. The signs and symptoms of hypopituitarism can vary by the hormones affected and may include everything from chronic fatigue and growth impairment to sexual dysfunction and the inability to produce breast milk.

The cause of hypopituitarism may be something you are born with or something that has directly damaged the pituitary gland (such as brain trauma, infection, or a tumor). The diagnosis can usually be made with blood tests and imaging studies. Hypopituitarism can often be treated with hormone replacement therapy.

doctor looking at brain CT scan
 Phil Boorman  / Getty Images

Types of Hypopituitarism

The pituitary gland, sometimes referred to as the "master gland," is a pea-sized organ located near the base of the brain. Its role is to either synthesize and/or secrete hormones that regulate bodily functions. The pituitary gland itself is divided into two lobes—the anterior (front) lobe and the posterior (back) lobe—each of which has different functions. Hypopituitarism can be broadly classified by the lobe affected:

Anterior lobe hypopituitarism is characterized by decreases in the hormones produced and secreted by the anterior pituitary gland. These include:

Posterior lobe hypopituitarism is charactered by decreases in hormones produced by the hypothalamus but secreted by the posterior pituitary gland:

  • Anti-diuretic hormone (ADH), which regulates how much water your kidneys conserve or release
  • Oxytocin, which helps induce labor contractions during pregnancy and also promotes breast milk production after birth

Panhypopituitarism is described when the function of both the anterior and posterior pituitary are impaired.

Hypopituitarism Symptoms

The symptoms of hypopituitarism can vary by the portion of the gland affected, the degree of hormonal impairment, and the age of an affected individual. In some cases, the effects may be subtle or and easily attributed to other conditions. At other times, the symptoms may be profound and debilitating.

Symptoms by Hormone Deficiency
Deficiency Symptoms
Adrenocorticotrophic hormone (ACTH) Children: fatigue, weight loss, delayed puberty, failure to thrive (in babies), low blood sugar
Adults: loss of appetite, weight loss, nausea, vomiting, muscle weakness, low blood pressure, prolonged infections, abnormal darkening of the skin
Follicle-stimulating hormone (FSH) Women: absent or irregular periods, slow or reduced breast growth, hot flashes, low sex drive, loss of body hair
Men: fatigue, muscle loss, abnormal breast growth, erectile dysfunction, low sex drive, osteoporosis, lack of facial or body hair
Growth hormone (GH) Children: short stature, delayed puberty, small teeth, lack energy, dwarfism
Adults: anxiety, depression, male pattern baldness, low sex drive, muscle loss, high cholesterol, insulin resistance, diabetes, abdominal obesity, heart problems
Luteinizing hormone (LH) Women: irregular periods, small or reduced breast growth, hot flashes, low sex drive, reduced breast milk production, infertility due the absence of ovulation
Men: low sperm count, small testicles, decreased muscle mass, low sex drive, erectile dysfunction, lack of facial or body hair
Melanocyte-stimulating hormone (MSH) Excess thirst, frequent urination, increased hunger, weight gain, sleeping problems, pain, lack of skin pigmentation, albinism
Prolactin (PRL) Womenfatigue, loss of body hair, inability to produce breast milk
Men: generally none
Thyroid-stimulating hormone (TSH) Fatigue, weakness, weight gain, constipation, hair loss, dry skin, muscle cramps, irritability, depression, memory loss, low sex drive, abnormal periods, sensitivity to cold
Anti-diuretic hormone (ADH) Excessive urination, frequent nighttime urination, excessive thirst
Oxytocin Anxiety, depression, pain, inability to produce breast milk

Causes

The causes of hypopituitarism can be broadly classified as being either congenital (occurring before or at the time of birth) or acquired (occurring after birth).

Congenital

Congenital hypopituitarism may be the result of a genetic mutation that affects the normal development of the pituitary gland during the embryo stage. There are no less than 25 mutations known to cause pituitary deficiency, including five known as combined pituitary hormone deficiency (CPHD) 1 through 5.

The majority are mutations passed from parents to child in an autosomal recessive pattern, meaning that both parents must contribute a CPHD mutation in order for the disease to manifest.

Among the rare genetic syndromes associated with hypopituitarism are:

  • Bardet-Biedl syndrome, which affects multiple body parts and organs
  • Kallman syndrome, which affects sex hormone production
  • Prader-Willi syndrome, which can lead to short stature, obesity, and intellectual disabilities

Congenital hypopituitarism can also occur at the time of birth due to pregnancy complications, including preterm birth, severe maternal anemiapregnancy-induced hypertension, placental abruption, and severe blood loss during the delivery (Sheehan syndrome).

Acquired

Acquired causes are those in which the pituitary gland is directly or indirectly damaged either by trauma, infection, disease, or certain medical treatments. Common examples include:

In some cases, the cause of hypopituitarism is unknown. Doctors refer to this as idiopathic hypopituitarism.

Hypopituitarism is a relatively rare condition, affecting around four of every 1,000 people. However, as many as 30% to 70% of people with a traumatic brain injury will exhibit some signs of pituitary gland impairment.

Diagnosis

The diagnosis of hypopituitarism is based primarily on blood tests but may also involve imaging studies to look for evidence of pituitary damage or deformity.

Chief among these are blood tests that measure the amount of the pituitary hormone in a sample of blood. This is not always as straightforward as it sounds. Deficiencies can be diagnosed in one of two ways:

  • Basal tests can detect hormone deficiencies based on a single test value. LH, FSH, prolactin, and TSH are all measured in this way. The blood is usually taken in the morning when hormone production is at its lowest.
  • Dynamic tests are those in which hormone levels are measured after a drug has been administered to stimulate the hormone under investigation. ADH, GH, and ACHT are measured in this way.

There are no blood tests able to accurately detect oxytocin deficiency. If oxytocin deficiency is suspected during pregnancy, a contraction stress test may be conducted to see if an intravenous dose of oxytocin can induce contractions.

Imaging studies may also be used to detect a pituitary tumor or other pituitary gland problems. The two most commonly used are:

If a genetic cause is suspected, specialized genetic testing may be performed. These are typically ordered when rare disorders like Prader-Willi syndrome are suspected and/or there is a family history of hypopituitarism.

Differential Diagnoses

Because the cause of hypopituitarism is sometimes difficult to pinpoint, the doctor will investigate other causes in the differential diagnosis. These include other diseases associated with hormonal deficiencies, including:

  • Addison's disease (an adrenal gland disorder)
  • Primary hypothyroidism (in which the problem is related to the thyroid gland)
  • Primary hypogonadism (in which the problem originates in the testes)
  • Primary ovarian insufficiency (in which the problem originates in the ovaries)
  • Polyglandular autoimmune syndrome (in which the immune systems attacks health glandular tissue)

Treatment

In most cases, people with hypopituitarism can be treated with lifelong hormone replacement therapy (HRT). Depending on the deficiency, a number of synthetic or natural hormones may be prescribed in pill, patch, or injectable form.

Some of the drugs used in HRT directly replace the depleted hormone. Others treated the so-called effector gland, meaning the gland that is directly stimulated by a pituitary hormone. (Examples include the thyroid gland which is regulated by TSH or the ovaries which are influenced by FSH and LH.)

Among the drugs commonly used in HRT for hypopituitarism:

  • Hydrocortisone is a synthetic form of cortisol, taken by mouth, that is used to treat an ACTH deficiency.
  • Estradiol is a synthetic form of estrogen, delivered in tablets or patches, that treats female hypogonadism caused by an LH or FSH deficiency. Progestin, a synthetic form of progesterone, is also sometimes used to prevent unwanted effects of estradiol.
  • Testosterone is a male hormone, typically delivered by injection and patch, used for men with hypogonadism due to LH or GH deficiency.
  • Human growth hormone (HGH) is a synthetic form of GH, delivered by injection, that is used to treat a diagnosed GH deficiency or hypogonadism.
  • Desmopressin, a manmade form of ADH available as a tablet or nose spray, is used in people with excessive urination due to an ADH deficiency.
  • Human chorionic gonadotrophin (HCG) is a hormonal often prescribed as an injection (often in tandem with FSH) to stimulate ovulation in women with impaired fertility due to an LH deficiency.
  • Levothyroxine is a synthetic thyroid drug used to treat hypothyroidism (low thyroid function) caused by a TSH deficiency.

Periodic blood tests will likely be needed to track your hormone levels and adjust treatment as needed. You may also need occasional CT or MRI scans to monitor a pituitary condition.

Surgery is uncommonly used to treat hypopituitarism unless there a tumor or growth that can reasonably be removed without harm. Instead, high-dose radiation may be used to shrink or control the tumor. If cancer is involved, chemotherapy may be prescribed.

A Word From Verywell

Hypopituitarism is an uncommon disorder that may be hard to recognize at first because the symptoms are often so non-specific. Even if a hormone deficiency is confirmed, it may take time the underlying cause is identified. In such cases, you will likely be referred to an endocrinologist who specializes in the diagnosis, treatment, and management of hormonal disorders.

To find one near you, you can either ask your healthcare provider for a referral or use the online locator offered by the American Association of Clinical Endocrinologists.

Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Gouden V, Jialal I. Hypopituitarism (panhypopituitarism). In: StatPearls. Updated February 24, 2020.

  2. Alexandraki KI, Grossman A. Management of hypopituitarism. J Clin Med. 2019;8(12):2153. doi:10.3390/jcm8122153

  3. Fang Q, George A, Brinkmeier ML. Genetics of combined pituitary hormone deficiency: Roadmap into the genome era. Endocr Rev. 2016 Dec; 37(6): 636-75. doi: 10.1210/er.2016-1101

  4. U.S. National Library of Medicine. Combined pituitary hormone deficiency. In: Genetics Home Journal. Updated 2020.

  5. Aminzadeh M, Kim HG, Layman LC, Cheetham TD. Rarer syndromes characterized by hypogonadotropic hypogonadism. Front Horm Res. 2010;39:154-67. doi:10.1159/000312701

  6. Du X, Yuan Q, Yao Y, Li Z, Zhang H. Hypopituitarism and successful pregnancy. Int J Clin Exp Med. 2014;7(12):4660-5.

  7. Kim SY. Diagnosis and treatment of hypopituitarism. Endocrinol Metab (Seoul). 2015;30(4):443-55. doi:10.3803/EnM.2015.30.4.443