Hypopituitarism is a rare disorder of the endocrine system, which is responsible for hormone production. The condition develops when the pituitary gland does not make enough hormones.

Hypopituitarism may appear suddenly or take many years to develop, depending on the cause. People with this condition often require lifelong treatment.

This article explains hypopituitarism, how it develops, the symptoms it causes, and how to manage it.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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Hypopituitarism is where the pituitary gland does not produce enough hormones. The pituitary gland is a small organ at the base of the brain. Its hormones help control how the body makes other crucial hormones.

A typical functioning pituitary gland produces adequate amounts of the following hormones:

  • Adrenocorticotropic hormone (ACTH): This hormone tells the adrenal glands to make cortisol, which helps the body cope with stress and inflammation.
  • Prolactin: This hormone stimulates milk production in people who are nursing. It also affects fertility and sexual function in both males and females.
  • Luteinizing hormone (LH) and follicle-stimulating hormone (FSH): These control the production of sex hormones and the release of eggs from ovaries. They play essential roles in puberty, menstruation, and fertility.
  • Growth hormone (GH): This stimulates bone, muscle, and tissue growth in children and adolescents. In adults, GH also helps control body composition, muscle and bone strength, metabolism, and heart function.
  • Thyroid-stimulating hormone (TSH): This triggers thyroid hormone production in the thyroid gland. These regulate metabolism, body temperature, growth, and development.
  • Oxytocin: The pituitary gland releases this hormone during childbirth, nursing, and sexual activity. Oxytocin helps with bonding, social behavior, empathy, and stress relief.

A shortage of these hormones affects the levels that the thyroid, adrenal glands, testes, and ovaries usually produce. These glands rely on pituitary hormones to function.

The symptoms of hypopituitarism depend on the particular hormone in low supply, as well as other factors, including:

  • the cause of the low pituitary hormone levels
  • age of onset
  • how quickly a person has a reduction in hormones

For example, as the thyroid has links to body temperature control, a person with low levels of TSH might feel particularly sensitive to cold. A child with low GH levels might experience difficulties with growth.

Symptoms can also include:

Symptoms in different populations

As hypopituitarism may reduce levels of sex hormones and GH, it may affect different features of general and sexual development. These might look different in males, females, and children.

Hypopituitarism can cause difficulties with growth, especially height and sexual development.

Symptoms in females

Symptoms in females may include:

Symptoms in males

For males, symptoms may include:

Causes

Hypopituitarism results from damage to the pituitary gland. This damage needs to have occurred to 75% of the pituitary gland to affect pituitary hormone levels.

This can be due to many reasons, including:

It is not always clear what causes hypopituitarism. This is known as “idiopathic hypopituitarism.”

A doctor will perform various examinations to diagnose hypopituitarism, such as:

  • Physical exam: This includes checking the skin and testing how blood pressure responds to lying down, sitting down, and standing up.
  • Blood tests: This may involve checking cortisol levels in the morning when levels are highest. Doctors test for testosterone levels at the same time of day. Using different tests, they may also test for TSH, GH, LH, FSH, and prolactin levels.
  • Stimulation tests: These involve injecting a medication to increase blood levels of pituitary hormones to test how they improve. High levels of one hormone but not others may suggest low pituitary activity. For example, if GH does not respond well to the test, it shows that the pituitary is not making enough of it.
  • MRI scan: This can help a doctor identify physical damage to the pituitary and show any tumors on or near the gland that might be causing hypopituitarism.

Treating the underlying cause of hypopituitarism is central to preventing further damage. However, treatment is often lifelong, as it is not possible to reverse the effects of the disorder.

Treatment includes:

Surgery

This often involves removing a tumor or lesion from the gland. These cause hypopituitarism in around 61% of people with the disorder. People will often still need to supplement hormone levels for life afterward. However, surgery sometimes improves how the gland works.

However, there is a 10–25% risk of hypopituitarism after tumor removal from the pituitary.

Hormone replacement therapy

This depends on the hormone that’s lacking. Replacement hormones act in place of hormones that the pituitary would produce rather than increasing the gland’s ability to produce more. Doctors supplement hormones with patches, injections, or oral medications. These might include:

  • a synthetic form of ADH called DDAVP
  • synthetic thyroxine, which replaces the thyroid hormone
  • testosterone for males
  • estrogen for females
  • cortisol for people with adrenal insufficiency

However, supplementation of GH is less common, except in children with GH deficiency.

Ongoing care

Regular checkups will be necessary for life. It can also help to wear a medical information bracelet or pendant that informs potential caregivers about the condition during emergencies.

A doctor will also advise on what to do in scenarios of sickness or stress. According to a 2021 study, hypopituitarism increases the risk of mental health disorders, such as depression and anxiety. Managing these, as well as periods of symptoms or medication side effects, can help people with hypopituitarism improve their quality of life.

According to the Endocrine Society, people with hypopituitarism may not have a lower life span, provided they continue to take their prescribed medications.

A 2017 review of 12 studies that included data on over 23,000 individuals found that hypopituitarism may have links to a lower age of mortality. The review concluded that the risk of lower life expectancy might be higher in the following groups of people with hypopituitarism:

  • females
  • anyone who received a diagnosis at a younger age
  • those who also have craniopharyngioma, a rare type of brain tumor
  • individuals who have received radiation therapy
  • those who have undergone brain surgery
  • individuals with a type of diabetes known as diabetes insipidus
  • those with low testosterone, or hypogonadism

Hypopituitarism refers to low levels of pituitary hormones. The condition often occurs due to a tumor but can develop suddenly or slowly due to a wide range of injuries and health issues. Hypopituitarism also affects hormone levels from other glands, which can lead to sexual or developmental issues and other symptoms.

A doctor diagnoses this condition using physical examination, blood tests, and MRI scans. Treatment is usually lifelong. It typically involves treating the underlying cause of hypopituitarism with surgery while supplementing levels of the low hormone.

Some people with hypopituitarism may have a reduced life expectancy. However, taking suitable medications and attending regular checkups can help improve lifespan.