In nephrogenic diabetes insipidus, the kidneys can't respond to a hormone that regulates fluid balance. Excessive urination and thirst are the results. Nephrogenic diabetes insipidus can be challenging to treat.
If you have diabetes, you probably know the warning signs of low blood sugar, or hypoglycemia. "It's been described best as a little like the feeling you get when you're sliding on ice in a car: panic, rapid heart rate, [and] sort of a sense of doom," says John Buse, MD, PhD, professor of medicine, chief of the division of endocrinology, and executive associate dean for clinical research at the University of North Carolina at Chapel Hill School of Medicine.
You also probably know that hypoglycemia...
Diabetes insipidus is caused by problems related to a hormone called antidiuretic hormone or ADH. ADH is produced in a part of the brain called the hypothalamus. It's stored in the pituitary gland. Release of ADH is triggered by fluid loss or dehydration. When it's released, it causes the kidneys to retain water. This results in a decrease and concentration of urine.
In nephrogenic diabetes insipidus, enough ADH is produced. But the kidneys are partially or completely blind to it. Typically, the kidneys' ADH sensors are missing or defective. As a result, ADH flows by without effect. The kidneys don't absorb enough water. Instead, they excrete abundant dilute urine as if no ADH were present.
What are the symptoms of nephrogenic diabetes insipidus?
The lack of ability by the kidneys to conserve water leads to the symptoms of nephrogenic diabetes insipidus. They include:
Excessive urine production (polyuria).
In some people, these symptoms can become extreme and cause dehydration. Excessive fluid losses can also cause electrolyte imbalances. Symptoms of electrolyte imbalances include:
For someone without nephrogenic diabetes insipidus, the extreme thirst it creates can be hard to understand. Some people need to drink a large glass of liquid every 15 minutes, all day, every day. And since the kidneys aren't holding that water in, that means a lot of bathroom breaks.
But why "insipidus"? People with diabetes insipidus aren't insipid, but their urine is. Insipid can mean dull or lacking flavor. Believe it or not, doctors long ago would taste urine to detect illness. Unlike diabetes mellitus, which results in sweet tasting urine, diabetes insipidus creates watery, flavor-free urine.