I just had a test done at the doctor's office that looked at the osmolarity of my blood. My doctor said I have hyponatremia, which happens with a lot of fluid loss and results in low sodium levels.
This article says the test can help doctors find out what the nature of an illness is. Is this test why my doctor said I have hyponatremia? He's a great doctor, he just isn't easy to talk to. Does anyone know anything about blood osmolarity tests?