Losing water?

Question
I've pretty much run out of ideas and need help please.



My symptoms:

Orthostatic hypotension (often but not always)

Constant dry mouth (more of a dry throat really)

Lack of energy

Bathroom runs often

Memory/thinking problems



I went to the doctor to see if I had diabetes and had blood work done and there were no problems - no diabetes, nothing.  I even got my own blood sugar meter and it never is that high.  I bought some urinalysis sticks and it showed nothing wrong.  



Drinking lots of water helps all the symptoms.  And eating smaller meals helps too as if I eat even a slightly big meal and don't drink enough water, I'm sure to get light-headed when I stand.  This started about 5 years ago and it hasn't gotten worse (because I drink aleast 3 liters of water a day).  



Also I'm not sure how related it is, but I get stiff necks and then headaches if I don't drink enough water.  It also happens if I sit and have my head down like I'm reading.  I'll end up cracking my neck and a headache will arise shortly after.



Anyway, I feel dehydrated, but I drink plenty of water.  My urine is never concentrated and I drink not in huge quantities at a time.



So if you any suggestions at all, I would very much appreciate it.



Thank you



Blood work:

18 chemistry tests including:

Glucose

BUN

Creatinine

Sodium

Potassium

Cl-

CO2

protein

anion gap

albumin

globulin

A/G ratio

total bilirubin

alk phos

alt

ast

calcium



Hematology:

WBC

RBC

HGB

HCT

MCV

MCII

MCHC

RDW

PLT

MVP

LY%

MO%

GRAN%

LY#

MO#

GRAN#



HbA1c


Answer
Hi Rob,



Thanks for asking my help on "Allexperts".



You may be suffering from a condition called Diabetes Insipidus.



In assessing patients with suspected diabetes insipidus (DI), the urine specific gravity of the first morning urine is helpful in assessing renal ability to concentrate urine. Dilute urine with a relatively high serum sodium and osmolarity effectively establishes the diagnosis. The serum sodium may be as high as 170 mEq/L, while the serum osmolarity is greater than 300 mOsm/kg.



The definitive diagnostic study is the water deprivation test, which can be used both to confirm the diagnosis and to distinguish between central diabetes insipidus (CDI) and nephrogenic diabetes insipidus (NDI) by response to a vasopressin analogue.



Please get yourself evaluated by a Nephrologist and discuss these points with him.



Sincerely,



Dr. Shah