Panhypopituitarism (Underactive Pituitary Gland)

The pituitary gland is located below the brain in the middle of the head.  It is not part of the brain but is an endocrine organ (gland).  It is the “master gland” and produces multiple hormones which control other glands such as the thyroid, adrenal glands, ovaries in women and testicles in men.

The hormones made by the pituitary gland include:

  1. ACTH (Adrenocorticotrophic hormone) – controls adrenal gland production of cortisol.
  2. Cortisol is a vital “stress hormone” which helps with the stress response of the body (maintaining Blood Pressure and circulation in times of physical stress), storing fat, fighting infection and regulating blood glucose levels
  3. TSH (Thyroid stimulating hormone) – stimulates the thyroid gland to produce active thyroid hormones, T4 and T3
  4. Growth hormone – influences growth and metabolism
  5. “Gonadotrophins” – FSH  & LH – these control the production of sex hormones – oestrogen & progesterone in women and testosterone in men
  6. Prolactin – controls lactation (breastmilk production)

Panhypopituitarism is the medical term for condition in which the pituitary gland fails to produce enough of the hormones it is supposed to make.

Symptoms and Signs

  • Fatigue & lethargy
  • Dizziness
  • Losing weight, loss of appetite
  • Feeling cold
  • Loss of body hair
  • Low sex drive (libido) in men;  low sperm  count in men
  • Symptoms of menopause; no menstrual periods, infertility and inability to breastfeed in women

Diagnosis

You will be required to have blood tests to check levels of all the pituitary hormones.  You may need an MRI of the pituitary gland.

Treatment

Treatment is aimed at hormone replacement of all deficient hormones including replacement of cortisol (hydrocortisone/ cortisone acetate), thyroid hormone (thyroxine), testosterone in men if appropriate, oestrogen in premenopausal women.

Special Precautions

ADRENAL CRISIS — Adrenal crisis refers to overwhelming and life-threatening adrenal insufficiency. The most common signs of adrenal crisis are shock (very low blood pressure with a loss of consciousness), dehydration, and an imbalance of sodium and potassium levels in the body. In some cases, shock is preceded by fever, nausea, vomiting, and abdominal pain, weakness or fatigue, and confusion. Adrenal crisis usually occurs after an infection, trauma, or another stressor.

Adrenal crisis is a life-threatening condition that requires emergency medical treatment. The patient or a family member or friend should immediately give an emergency injection of a glucocorticoid at the first signs of adrenal crisis. In the emergency department or ambulance, treatment usually includes giving several liters of a salt solution (saline) and an injection of a glucocorticoid (hydrocortisone or another form of cortisol) into a vein.

People with adrenal insufficiency from panhypopituitarism should learn as much as possible about their condition and should be aware of early warning signs of hormone deficiency. It is also wise to share this information with family, friends, and any caregivers, so that they can also identify signs of trouble and be prepared to act in case of adrenal crisis.

General precautions — People with adrenal insufficiency from panhypopituitarism should wear a medical alert bracelet or necklace. They should also carry an emergency medical information card that lists the names and doses of their daily medications and the clinician and family member(s) to call in case of emergency. It is extremely important to identify early symptoms of adrenal deficiency and adrenal crisis; a clinician can describe subtle symptoms that should not be ignored. In the presence of diarrhoea/ intercurrent infection/ physical stress, the regular dose of corticosteroid should be doubled and medical attention should be sought.