What is hypopituitarism?

Hypopituitarism is a disorder in which your pituitary gland does not make enough pituitary hormones.

The pituitary is a small gland located at the base of your brain. It's one of several glands that make hormones. Hormones are chemicals that send information and directions from one set of cells to another. The pituitary gland makes many types of hormones. These hormones affect many things, including bone and tissue growth, your thyroid gland, and sexual development and reproduction. Sudden loss of these pituitary hormones can lead to a life-threatening condition known as pituitary apoplexy.

What causes hypopituitarism?

The causes can directly affect the pituitary gland. Or they can indirectly affect the gland through changes in the hypothalamus. This is a part of the brain that is just above the pituitary gland. The hypothalamus makes hormones that help the pituitary gland work normally.

Direct causes include:

• Pituitary tumors (common cause).

• Poor blood supply to the pituitary gland.

• Infections or inflammatory diseases of the brain.

• Radiation treatment.

• Surgery to remove pituitary tissue.

• Autoimmune diseases.

• Brain injury.

• Genetic diseases and syndromes.

• Rare diseases, such as sarcoidosis and amyloidosis.

Indirect causes include:

• Hypothalamus tumors.

• Inflammatory disease or a disease that spreads to the pituitary, such as cancer. 

• Head injuries.

• Surgical damage to the hypothalamus or blood vessels or nerves leading to it.

• Certain medicines, such as opioids, that decrease hormone secretion from the hypothalamus.

What are the symptoms of hypopituitarism?

Symptoms are different for each person. They may happen over time or right away. They depend on which hormones the pituitary gland is not making enough of. These hormone deficiencies, and the symptoms they cause, include:

• Not enough gonadotropins (luteinizing hormone and follicle-stimulating hormone). This affects men and women who have not gone through menopause. Women may not have a menstrual period. They may have problems with fertility, vaginal dryness, and loss of some female traits. Men may have problems with fertility, sexual dysfunction, and loss of some male traits. Children will not go through puberty.

• Not enough growth hormone. Adults with this problem may lose bone and muscle mass. In children, it can lead to stunted growth and dwarfism.

• Not enough thyroid-stimulating hormone. This often leads to an underactive thyroid. It may cause lack of energy (fatigue), confusion, problems with cold temperatures, weight gain, constipation, and dry skin.

• Not enough ACTH (adrenocorticotropin hormone). This is rare but very serious. Your pituitary gland may not secrete ACTH if you have been taking adrenal steroid hormones and stop taking them suddenly. It leads to an underactive adrenal gland. You may have low blood pressure, low blood sugar, feel tired, and be easily stressed.

• Not enough prolactin. This is rare. Women who lack this hormone may not be able to make breastmilk after childbirth.

• Not enough antidiuretic hormone (also called vasopressin). This leads to increased urine output and thirst.

These symptoms may look like other health problems. Always see your doctor for a diagnosis.

How is hypopituitarism diagnosed?

Your doctor will ask about your health history. You will also need a physical exam. Other tests you may need include:

• Blood and urine tests. These tests measure hormone levels in your body.

• CT scan. This test uses X-rays and computer technology to make detailed images of your body.

• MRI. This test, without the use of X-ray, uses large magnets, radio waves, and a computer to make images of organs and structures within your body. (This is the preferred choice.)

• Stimulation test. This is an injection of medicines that will increase your pituitary hormones in the blood.

• Vision testing. Large pituitary tumors or cysts can affect your vision.

How is hypopituitarism treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

Treatment depends on what is causing the condition. The treatment goal is to have the pituitary gland work as it should. Treatment may include:

• Hormone replacement therapy.

• Surgery to remove a tumor.

• Radiation therapy.

When should you contact your doctor?

Tell your doctor if your symptoms get worse or you have new symptoms.

Key points about hypopituitarism

• Hypopituitarism happens when the pituitary gland is not active enough. It does not make enough hormones.

• It can be caused by things that directly affect the pituitary gland. Or it can be caused by things that indirectly affect the gland through changes in the hypothalamus.

• Symptoms depend on which hormones the pituitary gland is not making enough of.

• A CT scan, MRI scan, or blood and urine tests may be done for diagnosis.

• The treatment goal is to return the pituitary gland to normal function. Treatment may include hormone replacement therapy, surgery to remove a tumor, or radiation therapy.

Next steps

Here are some tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your doctor tells you.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.

• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are and when they should be reported.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your doctor if you have questions, especially after office hours or on weekends.