Antidiuretic Hormone (ADH) Profile Blood Test

Order this Antidiuretic Hormone (ADH) Profile to measure the concentration of ADH and osmolality in the blood to help detect an ADH deficiency, evaluate the body's fluid balance, and differentiate between the types of diabetes insipidus.

Osmolality is the concentration of dissolved particles like electrolytes and waste (creatinine and urea) in the bloodstream. Elevated osmolality levels activate the pituitary gland's production of the antidiuretic hormone (ADH) or arginine vasopressin (AVP). When ADH is produced, it usually causes the kidneys to conserve water rather than dispel it from the body through urine. The conserved water dilutes the blood and decreases osmolality. Therefore, the relationship between ADH and osmolality is to help balance the amount of water and acid levels in the body.

Excessive levels of ADH are associated with a condition known as the syndrome of inappropriate antidiuretic hormone" (SIADH). SIADH is caused by conditions that stimulate the overproduction of ADH, leading to water retention, low blood sodium, and decreased blood osmolality. However, if there is a decrease in ADH production or the kidneys are incapable of responding to ADH, it can result in an ADH deficiency. An ADH deficiency can lead to excess water loss through the kidneys, the urine is more dilute, and the blood becomes more concentrated (higher osmolality). As a result, individuals can experience excessive thirst, frequent urination, dehydration, and high sodium levels in the blood.

A rare condition caused by an ADH deficiency is diabetes insipidus. The two main types of diabetes insipidus include:

• Central Diabetes Insipidus is associated with damage to the pituitary gland or hypothalamus that prevents adequate antidiuretic hormone (ADH) production. It may be inherited or acquired through conditions like cancer, head trauma, and infections (encephalitis or meningitis).
• Nephrogenic Diabetes Insipidus disorder is related to the kidneys' incapacity to properly process antidiuretic hormone (ADH). It may be inherited or acquired through conditions like kidney disease.

Common symptoms of diabetes inspidus include:

• Excessive thirst
• Excessive urination (clear urine)
• Frequent nighttime urination
• Nausea
• Dizziness upon standing
• Fainting

Individuals may order the Antidiuretic Hormone (ADH) Profile if they are experiencing symptoms of an ADH deficiency or diabetes insipidus, and to monitor their fluid balance levels. The Antidiuretic Hormone (ADH) Profile may also be ordered in conjunction with an Electrolyte Panel and a Copeptin Blood Test.