Hypopituitary

Hypopituitary Overview

Hypopituitarism is a condition in which the pituitary gland (a small gland at the base of the brain) does not produce one or more of its hormones or not enough of them. This condition may occur because of disease in the pituitary or hypothalamus (a part of the brain that contains hormones that control the pituitary gland). When there is low or no production of all the pituitary hormones, the condition is called panhypopituitarism. This condition may affect either children or adults.

The pituitary gland sends signals to other glands (eg, thyroid gland) to produce hormones (eg, thyroid hormone). The hormones produced by the pituitary gland and other glands have a significant impact on the body’s functions, such as growth, reproduction, blood pressure, and metabolism (the physical and chemical processes of the body). When one or more of these hormones is not produced properly, the body’s normal functions can be affected. Some of the hormones like cortisol and thyroid hormone may require prompt treatment, whereas others may not be life threatening.

The pituitary gland produces several hormones. Some of the important hormones are as follows:

• Adrenocorticotropic hormone (ACTH) is a hormone that stimulates the adrenal glands (glands on the kidneys that produce hormones). ACTH triggers the adrenal glands to release a hormone called cortisol, which regulates metabolism and blood pressure.
  
  
• Thyroid-stimulating hormone (TSH) is a hormone that stimulates production and secretion of thyroid hormones from the thyroid gland (a gland in the hormone system). Thyroid hormone regulates the body’s metabolism and is important in growth and development.

• Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are hormones that control sexual function in males and females. They are also known as gonadotropins or sex hormones (eg, estrogen, testosterone).
  
  

• Growth hormone (GH) is a hormone that stimulates normal growth of bones and tissues.
  
  

• Prolactin is a hormone that stimulates milk production and female breast growth.
  
  

• Antidiuretic hormone (ADH) is a hormone that controls water loss by the kidneys.
  
  

In hypopituitarism, one or more of these pituitary hormones is missing. The lack of hormone results in a loss of function of the gland or organ that it controls.

Hypopituitary Causes

A loss of function of the pituitary gland or hypothalamus results in low or absent hormones. Tumors can cause damage to the pituitary gland or hypothalamus and can therefore result in a loss of function. Damage to the pituitary gland can also be caused by radiation, surgery, infections (eg, meningitis), or various other conditions. In some cases, the cause is unknown.

Hypopituitary Symptoms

Some persons may have no symptoms or a gradual onset of symptoms. In other persons, the symptoms may be sudden and dramatic. The symptoms depend on the cause, rapidity of onset, and the hormone that is involved.

 

• ACTH deficiency: Symptoms include fatigue, low blood pressure, weight loss, weakness, depression, nausea, or vomiting.
  
  
• TSH deficiency: Symptoms include constipation, weight gain, sensitivity to cold, decreased energy, and muscle weakness or aching.
• FSH and LH deficiency: In women, symptoms include irregular or stopped menstrual periods and infertility. In men, symptoms include loss of body and facial hair, weakness, lack of interest in sexual activity, erectile dysfunction, and infertility.
  
  
• GH deficiency: In children, symptoms include short height, fat around the waist and in the face, and poor overall growth. In adults, symptoms include low energy, decreased strength and exercise tolerance, weight gain, decreased muscle mass, and feelings of anxiety or depression.
  
  
• Prolactin deficiency: In women, symptoms include lack of milk production, fatigue, and loss of underarm and pubic hair. No symptoms are seen in men.
  
  
• ADH deficiency: Symptoms include increased thirst and urination.