What Is Vasopressin?

This natural hormone is used in the management of several life-threatening conditions, including bleeding abnormalities and septic shock.

Vasopressin is a naturally occurring hormone that helps control various bodily functions.

By maintaining the appropriate volume of water in the space that surrounds cells within the body, vasopressin allows proper cellular function.

Vasopressin (also called antidiuretic hormone) plays a role in regulating the circadian rhythm — the periods of sleepiness and wakefulness in a 24-hour cycle.

Vasopressin also helps maintain the body's internal temperature, its blood volume, and the proper flow of urine from the kidneys.

Both men and women naturally produce vasopressin, yet men experience its effects more strongly because of how it interacts with the male sex hormone testosterone.

Nerve cells at the base of the brain (hypothalamus) make and transport vasopressin to the pituitary gland, which then releases the hormone into the blood stream.

Pain, stress, and certain drugs — such as opiates (narcotics) — can trigger the release of vasopressin.

What Is SIADH?

If your body produces too much vasopressin, your kidneys may retain water.

A condition called syndrome of inappropriate antidiuretic hormone secretion (SIADH) can occur when the body produces too much vasopressin.

In SIADH, excess water retention dilutes the blood, resulting in a low sodium concentration.

Excess vasopressin can be caused by:

• Drug side effects
• Diseases of the lungs, chest wall, hypothalamus, or pituitary gland
• Tumors, especially cancerous ones

What Does Not Enough Vasopressin Do?

If you don't have enough vasopressin, your kidneys may excrete too much water. This causes frequent urination and can lead to dehydration, as well as low blood pressure.

Lack of vasopressin can be caused by:

• Damage to the hypothalamus or pituitary gland
• Drinking an excessive amount of water

Vasopressin in Medical Practice

While vasopressin occurs naturally in the body, healthcare providers also use a synthetic vasopressin drug to help manage the following conditions:

• Diabetes insipidus (a condition in which the kidneys are insensitive to vasopressin because of a tumor, trauma, medication side effect, or inflammation of the pituitary gland or hypothalamus, leading to water loss through frequent urination)
• Bleeding abnormalities such as von Willebrand disease and mild hemophilia A
• Esophageal variceal hemorrhage (in which veins in the esophagus become enlarged and bleed)
• Asystolic cardiac arrest (in which the heart stops beating, with no electrical activity detected)
• Septic shock (a serious condition involving extremely low blood pressure caused by an infection)

Vasopressin is given in a hospital or clinical setting, and is administered by injection into a muscle or vein.

If you have diabetes insipidus and don't need to be treated in a clinical setting, your healthcare provider may show you how to prepare and inject vasopressin at home.