Nephrogenic diabetes insipidus is a rare condition that results in excessive urination and thirst. It occurs when the kidneys no longer respond to the hormone arginine vasopressin (AVP).

Symptoms occur when the kidneys do not respond or are resistant to AVP — a hormone that triggers the kidneys to conserve water. Consequently, researchers have renamed nephrogenic diabetes insipidus to arginine vasopressin disorder resistance (AVP-R).

When someone has AVP-R, the main symptoms include a frequent need to pass light-colored urine and excessive thirst. People are more likely to develop AVP-R when they have a family history of the disease or are taking medication that can increase the amount of urine they produce.

Generally, treatment involves the prevention of severe dehydration.

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Formerly known as nephrogenic diabetes insipidus, AVP-R occurs when the kidneys no longer respond to AVP and flush too much fluid away as urine.

AVP, also known as antidiuretic hormone, is a hormone that helps the kidneys control the amount of water and salt present in the body. The hypothalamus in the brain produces AVP and secretes it into the blood through the pituitary gland. AVP works by signaling the kidneys to reabsorb water back into the body.

When the kidneys do not respond to AVP, the body cannot maintain water balance and symptoms such as excessive thirst begin to develop. If a person does not receive treatment for AVP-R, they can develop severe dehydration and other complications.

The three other types of AVP include:

Arginine vasopressin deficiency (AVP-D)

When the body does not produce enough AVP from the hypothalamus (a structure deep within the brain), the pituitary gland does not release the necessary amount the kidneys need. Consequently, the kidneys continue flushing fluid away and do not conserve it. Previously, AVP-D was known as central diabetes insipidus.

Gestational form of arginine vasopressin disorder (gAVP-D)

This type was formerly known as gestational diabetes insipidus. As the name suggests, it is a form of the condition that occurs during pregnancy.

Sometimes during pregnancy, the placenta makes an excessive amount of an enzyme that breaks down AVP. Additionally, people who are pregnant with more than one baby have a higher likelihood of developing gAVP-D, as they have more than one placenta.

Primary polydipsia

Formally known as dipsogenic diabetes insipidus, this type describes when a problem with the hypothalamus causes extreme thirst and urination. Typically, this can happen when the brain sustains injury from surgery, infection, and inflammation. Tumors can also cause symptoms, in addition to some medications.

A lack of response to AVP from the kidneys causes excessive fluid flushing. The body makes enough AVP, but the kidneys are resistant to it and continue producing urine even when a person is dehydrated.

Factors that can affect the response to AVP from the kidneys include:

  • medications that treat bipolar disorder, such as lithium
  • low blood potassium levels
  • high blood calcium levels
  • blockage in the urinary tract
  • inherited genetic condition
  • chronic kidney disease, though this is rare

The main symptoms of AVP-R include:

  • a frequent need to urinate, passing up to 20 quarts of urine a day
  • passing large amounts of light-colored urine
  • extreme thirst

As the body will lose too much fluids and electrolytes to function correctly, a potential complication of AVP-R is dehydration. Therefore, a person with AVP-R may also experience:

  • dry mouth
  • dizziness
  • nausea
  • feeling light-headed when standing
  • fatigue
  • noticeable drop in concentration
  • feeling faint

A doctor will ask a person questions about their family medical history and general health. They may also use:

  • Urinalysis: This test measures how concentrated or diluted urine is.
  • Blood tests: Measure blood sodium and potassium levels, in addition to other substances.
  • A water deprivation test: This test measures urine volume after a person has not drunk any water for several hours.
  • MRI: This imaging scan detects any damage to or tumors in the hypothalamus and pituitary gland.
  • Stimulation tests: A person receives a drug that stimulates the production of AVP, which also causes an increase in copeptin. The type of AVP a person has depends on how blood copeptin levels have changed.
  • Genetic screening: Detects any changes in a person’s genes that may cause AVP-R.

The results of these different tests help a doctor determine the type of AVP a person has and rule out other conditions, such as diabetes mellitus.

The main goal of treatment is to prevent dehydration, and what a doctor suggests depends on the cause. For example, if AVP-R is a side effect of medication, a person will likely need to try another drug.

Other treatment options include:

  • low sodium and protein diet
  • thiazides, a type of diuretic
  • indomethacin or amiloride — which are nonsteroidal anti-inflammatory drugs (NSAIDs)

AVP-R, formally known as nephrogenic diabetes insipidus, is a condition that affects the kidneys. AVP-R occurs when the kidneys no longer respond to AVP and fail to retain water. Symptoms include excessive urination of dilute urine and extreme thirst. A potential complication of AVP-R is severe dehydration, due to a person losing a lot of fluids.

The treatment a doctor recommends for AVP-R will depend on the cause. For example, if medication is making the kidneys resistant to AVP, a person may need to switch therapies.