My creatinine levels have gone up, my GFR has gone down to 40.

My levels do fluctuate. I find that if I am more active then normal, have too much caffeine and not enough water , or eat more "prepared foods" then usual ... it can affect my kidneys and make them work harder. I also try to be well hydrated for any testing.
Our kidneys are part of a whole system and stress on one part can shift others. But it doesn't necessarily mean that it will stay there. Do the things you can... rest, light exercise, good healthy food and stay hydrated! Also don't worry to much...stress is hard on our bodies. Do something you enjoy, sit in the sun to get some natural vit d .
Hoping your levels adjust and the appointment is helpful.

@nscappa We need to look at trends, not just a single lab report. Sit down with a cuppa tea and a few cookies, and write out a list of questions for your doctor. As @lbrockme mentioned, it doesn't take much to get our values off kilter. Think back and see if you can connect anything unusual to your normal routine.

Worrying will not do you any good. On the other hand, being aware of changes in your lab values is a good thing, so you can help catch any issues before they become a big deal. So, kudos to you on this point! Relax, write out those questions, and take a deep breath. You got this!
Ginger

Hi Ginger,

Once again thanks so much for your reply. You make sense and I will write down any questions and concerns with my doctor. I don't know if it's something that I'm doing or not doing. Ginger, I'm wondering if kidney disease can run in families. Thanks again! Nancy : )

Thanks so much for addressing my issue in such a friendly way. Both you and Ginger are so great with your advice and your own experiences. I need to take in more water and I try to get at least 40 to 60 ounces but the 60 is a bit tough. I don't exercise (depression) and other things are difficult for me too. I just don't want my CKD3 advance so if it's something I need to do then I will certainly try harder. I think I've slacked off somewhat. I eat cabbage (I saute it), I love beans and I do rinse them to get rid of the majority of the salt. Well, I won't bore you with my menu : ). Again, thanks so much for your quick reply and I will post after my appt.
Nancy : )

You got this! Hang in there!

My eGFR bounces around from 36 to 51. Hydration is a big factor but there are mysteries. My doc says muscle wasting can make it go down, as can low blood pressure or heart issues. My doc does a Cystatin C which gives a different GFR not influenced by those other factors and while my creatinine based one was 36-41, my Cystatin C was 51-55.

My nephrologist said the Cystatin C is more accurate measure.

Thank you so much. I'll check mine. Nancy : )

Thank so much for the information which is really helpful. I like the fluctuations that you mentioned, and it makes me worry less. Thanks again! Nancy : )

Yes Cystatin C is more accurate because it is not affected by muscle changes.