Anyone know about kidney GFR?

[Whatcouldpossiblygowrong]

Here are the headlines.
i feel like crap.
I have felt like crap for a long time.
I finally went to the drs and asked for a set of bloods not really knowing what to look for
They've come back saying everything is within the normal range
But my eGFR is in the 70s (says should be 90s). I don't have any other risk factors that would explain it being low and don't understand why it is.
Now wondering if there's any way that a decline in kidney function is related to why I'm always ill and tired?
Is it worth going back to see the dr or will it be a total waste of NHS time?
Already feel like a time waster and suspect they just think - you're a mum, and you work, yes you're tired. But I'm exhausted all of the time and go from cold to flu to cold. fed up!

Also - if there's another board better suited let me know - couldn't think where to post just hoping others have advice

70 is normal. only below 60 is considered chronic kidney disease and in any case that can be normal with increasing age. only exception is if you have another marker of renal disease eg. protein in the urine

PS I don't know your ethnicity but you need to multiply by 1.21 if you are African or Caribbean so it would be even more normal then!

If you're still feeling crap then go back and talk to your GP (if only to ask more about your eGFR although it sounds like Pigs should have put your mind at ease there).

I was feeling very tired a few years ago. I knew I wasn't anaemic as I could run and cycle but I was daydreaming about sleep even when exercising. My bloods didn't show anything but a friend who works in medical research suggested I tried taking vitamin D. I live in the north and a few friends had been told they had low levels so I thought it wouldn't do any harm. It's not resolved it perfectly but I certainly have more energy than I did. Maybe it's worth a try if your GP can't find anything wrong? (I take the 25microgramme ones from Boots so more than you'd get in a multi vitamin.)

Thanks!
I will try vit D. Also someone suggested taking iron which probably won't hurt though iron levels look good at mo.
This table suggests my score isn't brilliant - although NICE guidelines wouldn't diagnose with me with CKD -
www.kidney.org/sites/default/files/docs/12-10-4004_abe_faqs_aboutgfrrev1b_singleb.pdf
So I think I will go back and see dr again anyway. I'm white British and quite young so I think even adjusting for age and ethnicity they are on the lower side.
Even if I haven't officially met the criteria for a diagnosis I wonder if I should put things in place to protect the kidney function

It can be dehydration at the time of the test.

Any update ? I’m in the same boat! Mine was 76! No reason for it