General information:

Antidiuretic Hormone (ADH), also called arginine vasopressin (PAH), is produced by the hypothalamus and stored in the posterior pituitary gland. It regulates the water balance in the body by controlling the amount of water the kidneys absorb.

Normal anti-diuretic hormone is released from the pituitary in response to received data for increased osmolality or reduced blood volume. The kidneys respond to the antidiuretic hormone, conserving water and producing more concentrated urine. The retained water returns to the bloodstream, lowering the osmolality of the blood and increasing the circulating volume. If this is not enough to restore the water balance, it stimulates the thirst for the affected person to take up more fluids.

There are a number of disorders, conditions and medications that affect either the amount of antidiuretic hormone released or the sensitivity of the kidney to it.

The study of ADH levels is recommended in the following cases:

• In the presence of symptoms such as headache, nausea, vomiting, confusion
• To determine the causes of hyponatraemia (low sodium levels)
• In case of suspicion of tasteless diabetes.

SAMPLE REQUIRED:

Venous blood in the morning in fasting

 

Key words:

Antidiuretic hormone (ADH)