Diabetes Inspidus question...

Daytonite, BSN, RN · Mar 2, 2008

if you have diabetes insipidus you have a increased urine output and hypernatremia. how is this possible? i think i am confused, i thought sodium follows water so wouldn't the sodium be excreted through the urine as well?

in diabetes insipidus there are huge losses of water through the kidneys. sodium, however, is not lost through the kidneys because the kidneys still have the ability to concentrate urine and they will hold sodium back. in di patients tend to become dehydrated because of the massive amounts of water that they do lose through the kidneys which is how they end up with hypernatremia. it is because of their dehydrated state. if they retain the ability to be thirsty and drink water to replace the fluid losses, the hypernatremia won't be as pronounced.

also a question about a school age child before being diagnosed with diabetes mellitus: would the child first experience: stomach pain or bed wetting suddenly

the symptoms of dm in order of occurrence are:

hyperglycemia (elevated blood sugar)
glycosuria (glucose in the urine)
polyuria (excessive urine production)
polydipsia (excessive thirst)
polyphagia (increase in food intake)
itching

what do you think? my answer would be sudden bed-wetting. the symptoms of type i dm usually occur suddenly in contrast to type ii whose symptoms occur over a long period of time.

fyi. . .one of my cats developed insulin dependent dm two years ago. the signs that i missed were that she was losing weight, but also that she was peeing all the time.

the reason for the peeing is because the kidney is trying to rid the blood of the glucose that is building up in it so will start putting out urine to try to excrete the excess glucose. the renal threshold for glucose is something like 250. so when blood glucose goes over 250 the kidneys will start trying to dump it via the renal system. in the process, they become dehydrated and if the process isn't stopped the person will eventually end up in ketoacidosis. kids will wet the bed because they are so deeply asleep that they are unable to awaken to get up and go to the bathroom. ever try to wake a kid in the middle of the night? good luck.

fizzgigger · Mar 2, 2008

I see! Okay, I was really confused. My book was not giving any explanations, just facts. I'm the type of person who digs deeper. As for the DM answer, your right. It was a test question and I put stomach ache because in class my teacher said any child with DM will be throwing up excessively. I have it on tape too, but when I go the answer wrong I was like WHAT? I wanted to clarify it before I took it up with the teacher. I forgot that polyuria was a s/s. I wonder how many other people missed it due to her lecture? Hmmm. Thanks so much again, your always a wonderful help. :bow:

Sorry I don't post much to help other or just to communicate but I'm so busy with school. I do hope you understand.

yoginurse2b · Mar 3, 2008

When you think of Diabetes Insipidus, you have to know there's a decrease in ADH (antidiuretic hormone) level. Therefore, increase urine loss. But water loss is more than sodium loss, thus causing the urine to be concentrated and leads to hyperNa.

ADH --> low ADH --> increase H20 loss in urine --> increase concentration of urine --> hyperNa (and possible hypovolemia)