Question about diagnosis

smurfaggie07

How does a doctor diagnose diabetes? What tests do they run?

CRody44

Most of the blood sugar tests are done after drawing a vile of blood. Most of them test for your A1c which is a three month average of the level of sugar in your blood. .

JaceyMarieS

Often, a fasting plasma glucose is run as a part of standard blood work.


If the FBG is above 100 but below 126, a doctor may or may not recommend further testing and will most certainly recommend lifestyle changes

If the FPG is above 126, most doctors will then order either

1. An HbA1c blood test (mentioned above) An A1c reading from 5.7 - less than 6.5 indicates pre-diabetes and the doctor will again recommend lifestyle changes. An A1c reading at 6.5 or above indicates diabetes. The A1c has recently become the diagnostic standard, but it is important to remember that with the A1C, a lower result never rules out diabetes, but a higher result implies that your have either impaired fasting glucose or impaired glucose tolerance or both.

and/or

2. An Oral Glucose Tolerance Test - You will be asked to drink a sweet liquid containing a measured amount of glucose - usually 75 grams. Blood samples will be collected at timed intervals of (sometimes 30 minutes) 1, 2, and (sometimes) 3 hours after you drink the glucose. Blood samples may also be taken as soon as 30 minutes to more than 3 hours after you drink the glucose. A 2 hour blood glucose reading above 200 indicates diabetes, while a reading between 140-200 indicates pre-diabetes.


Technically, you need to have two tests in the diabetes range to be diagnosed. This isn't to say you need 2 A1c's or 2 OGTT results. any combination of 2 abnormal results from any of the 3 is enough.

Except for gestational diabetes testing, the OGTT is rarely used for primary diagnosis anymore - probably due to the time involved. However, it is an excellent diagnostic test. My A1c (5.5) and FBG (generally around 93) mean that a physician who wasn't aware of my diagnosis wouldn't realize I was diabetic. However, my diabetes is merely controlled....not "reversed" or "cured"...and an OGTT would quickly reveal this.

smurfaggie07

Thank you both for your information. I want to see about getting the A1c tested, even though my FBG has been normal as far as I know.

ETA: nevermind, I found old bloodwork and found the A1cs... both were 5.0, in the acceptable range. But my doc has me down for Metabolic Syndrome and on metformin.

deeschange

Excellent response. I know that I am much better informed by the information that you provided.