Adventures of a Kidney Donor

October 20, 2012

The Curious Case of My GFR Rate

Filed under: Medical — by anne315 @ 4:43 pm
Tags: ,

Hang on to your hats because this gets a little complicated. I am NOT a medical professional so this is just for information and referral to other sources. Please consult a medical professional if you have this issue or are curious about it.

Glomerular filtration rate (GFR) is a test used to check how well the kidneys are working. Specifically, it estimates how much blood passes through the tiny filters in the kidneys, called glomeruli, each minute.  Older people will have lower normal GFR levels, because GFR decreases with age. Your age, race and gender are factors in determining what is normal. The traditional stages of kidney disease as defined by GFR:

OK, are you with me so far?

My GFR saga began one day a few weeks ago when my doctor called me. She didn’t like my GFR number–it was too low–so she wanted me to re-test but without fasting beforehand. Her theory was that maybe I hadn’t had enough fluids before the test. So…I re-tested and the GFR rate was still too low. Technically, my number falls in the stage 3 Chronic Kidney Disease (CKD) range. Well that sounds scary.

Her next sentence made me freak out a little. “We want to ultrasound your kidney.” EEEK. I pulled myself together and started to think. My doctor is great and I am glad she is vigilant, but general practitioners don’t always understand what a nephrologist would. Maybe we should talk to the kidney people. So she called my coordinator at University of Michigan. In the meantime I work at a library so I got my hands on as much as I could about GFR rate. A lot of what I read indicated that the GFR rate will go down for kidney donors but this doesn’t necessarily mean that your kidneys are failing. Often it will go down then back up. It is an estimated number. Also, you need to look at it in relation to other measures such as albumin and proteinuria  levels, your blood pressure and blood glucose.

My other kidney numbers are normal so my transplant coordinator advised to re-test in a year. I am taking this seriously, but I don’t think I am in chronic kidney failure. If kidney donors were experiencing kidney and heart disease in great numbers as a result of low GFR rates, we would have heard about this by now. Many kidney donors experience a drop in GFR, and there is some discussion that there is a need to re-classify  these numbers for kidney donors.

All pretty confusing. The lessons from this I think are:  Get your kidney panel tests done yearly. General practitioners (not their fault, just the nature of medicine) don’t always know enough about kidney issues so consult a nephrologist or your transplant coordinator if the numbers aren’t normal. Don’t assume that you have CKD but don’t ignore your numbers either.  Read as much as you can. Some helpful sources for me were:

Go to List of Resources on Kidney Donation


  1. May I send this to a reporter I know who is doing a series of stories on the good and bad of the transplant industry?

    Sent from my iPhone

    Comment by ufogal — October 20, 2012 @ 5:39 pm |Reply

  2. Thank you

    Comment by ufogal — November 5, 2012 @ 10:12 am |Reply

  3. The only sites that talk about low GFR for single kidneys are the donors sites…as I am living with one kidney after cancer took the other.. I could find NO info that my lower GFR was “normal with a reduced kidney to filter. So YES both donors and single kidney patients will have reduced function, but it doesn’t quite mean you are sick at stage 3b..even if the number says so.

    at age 63.5 gfr 80 would be normal for me, but at 40 for my one kidney is fine.. I STILL have CKD but not the level of ‘sickness’ as a 2 kidney person..I still follow a renal diet, am on BP meds now, and wish some one saved me a lot of worry by knowing this my doc did not, hard to find answers til a nephrologist told me.

    Comment by Charmaine — January 12, 2013 @ 12:45 am |Reply

  4. So, what happened a year later?

    Comment by Jessica — April 24, 2014 @ 4:52 pm |Reply

    • My GFR rate is going back up steadily. (It does reduce somewhat with age even for people with two kidneys.)

      Comment by anne315 — April 25, 2014 @ 10:05 am |Reply

  5. I’m so glad I came across this – I’m not a donor, but have had fluctuating GFR since April….. creatnine is fine, urine is fine……..but my doctor wants an ultrasound. I feel like it’s overkill, but have been doing a lot of reading – and am scared enough to go do it. Lowest GFR was 47. Recently went from 50 to 55…. so I kind of suspect some vitamins/supplements, so will be decreasing those for now….. really have myself scared!!

    Comment by Trish — December 3, 2015 @ 5:16 pm |Reply

RSS feed for comments on this post. TrackBack URI

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Create a free website or blog at

%d bloggers like this: