October 2, 2000
Diabetes Insipidus
Question from Racine, Wisconsin, USA:
My 4 year old son, if he could, would drink 24 hours a day. He has always drunk a lot, ever since birth. He was tested early, and we were told there were no signs of diabetes and that he just liked to drink. Well, we accepted that, and didn’t think anything more about it. However, he was taken to the emergency room several times from the age of one to three because he was very lethargic. He was dehydrated, so they pumped him full of fluids, and sent him home. Hours later, he would be fine. He was never on any medication, and has been fine for close to two years. Now, he asks for drinks every half-hour, and when told “no” he doesn’t need it”, he cries, and will sneak it. either from the bathroom, or has even been caught drinking from the faucet of the water cooler in the kitchen. I kept track of how much he drank one weekend at his grandmother’s. He finished almost a five gallon jug of water by himself. When asked why he wants another drink, he says ” my brains not cold yet “. Now, I know that’s probably just something a four year old would say. When he does drink, he drinks it straight down, never lasts more than thirty seconds.
He will be going back east next week, and will be checked out, but will we once again just be told ” He just likes to drink “. I hope not. I hope for some answers.
Answer:
I think that you should ask your doctor about the possibility that your son has a condition called diabetes insipidus. This may be due to an abnormality, often inherited, which leads to an inability to concentrate urine. In consequence, there is an exaggerated need for water. The fact that your son was apparently free of this problem for two years also suggests that he might instead have “psychogenic polydipsia” or “compulsive water drinking”.
Simple tests of the specific gravity of the urine and of the concentration of plasma and urine (osmolality) can indicate the diagnosis, although the defining test rests with the ability to concentrate urine after a short, enforced thirst. More complicated tests are needed to tell the difference between the neurogenic and kidney based disorder. Treatment with drugs like Desmopressin may be very successful. I do not think that this story is at all suggestive of ordinary diabetes (diabetes mellitus).
DOB
