I do not currently have health insurance.
I am a grad student and with the 68 dollar payment of my 'student health fee', I can get free doctor visits at my university. The doctor did the urine test for sugar and found nothing. For 11 dollars they can do a blood test for Diabetes (which runs in my family).
With or without insurance, the doctors in Las Vegas are a joke...
Not sure what to check next...
I spent over 2 hours to see the MD for 5 minutes!
I guess this is the reason we should have national health insurance; so people can get the appropriate attention. If you have not asked the physician about the excessive thirst you need to mentioned this. It's not enough in your case just to have asked him to rule out diabetes mellitus. You may have more going on.
1. A urinalysis is only an inexpensive screening test. A blood test is definitive. Diabetes is defined as a fasting blood sugar > than 126 mg/dl.
2. Evaluating a concentrating defect of the kidney is very complex and is in the realm of specialists such as endocrinologist or neprhrologists.
The screening test for a concentrating defect is not that complex. The test is called a water deprivation test. The patient under a physician's observation is deprived of water for a defined time period of time. At the end of this period the osmolality of the urine is checked. A normal person will have a highly concentrated urine and high osmolality. A person with a concentrating defect will have an inappropriately dilute urine and low osmolality. This test does have risk. Someone with a significant defect can get severely dehydrated and develop shock.
Good luck getting through the maze which is the US health care system. Whatever you do don't give up. Talk to the physician about the problem