Sometimes kidney damage occurs from use of nephrotoxic medications. Why don’t the kidneys respond to the ADH? It may be due to some kind of kidney infection or damage. They are getting the ADH, but they don’t respond and don’t reabsorb more water. They are not responding appropriately to the ADH signal. With nephrogenic diabetes insipidus, the posterior pituitary gland is actually releasing the correct amount of ADH. The hypothalamus and pituitary gland are in the brain, so that’s how you can remember neurogenic diabetes insipidus. The prefix neuro- in neurogenic means nervous system, or more specifically, brain.
Without enough ADH being released from the posterior pituitary gland, the kidneys are not getting the signal to reabsorb water. Neurogenic diabetes insipidus happens when there is some kind of trauma or tumor in the hypothalamus or pituitary gland which is causing insufficient ADH to be released. Pathophysiology Neurogenic diabetes insipidus The word insipidus comes from Latin meaning “tasteless,” referring to the diluteness of the urine. The word diabetes comes from Latin and Greek meaning “siphon” or “to pass through,” referring to excessive urination common with the disease.
If you would like more in-depth information about ADH, we gave an overview of ADH in the pathophysiology section of this playlist. With diabetes insipidus, the body has too little antidiuretic hormone (ADH), and with SIADH, the body has too much ADH. What is the difference between SIADH and DI?