@sheeb - Welcome to Mayo Clinic Connect. I understand your concern and I want to commend you for being proactive about your own health by looking for more information.
I would like to share this link to Mayo Clinic Patient Health Information for Chronic Kidney Disease. You can read a full explanation of chronic kidney disease.
https://www.mayoclinic.org/diseases-conditions/chronic-kidney-disease/symptoms-causes/syc-20354521
You might ask your doctor to refer you to a nephrologist if he has not already done so.
Keep in touch, and let us know what you find out. We welcome any additional questions that you may have.
Rosemary

@sheeb, I am not sure I have mentioned this to you, but there are some signs you can watch for. Most importantly, air bubbles / foam in your toilet after urination. Make sure the urine hits the water directly, not the side of the toilet. Mine creates an inch or two of froth after each urination. That is a sure sign of kidney failure due to excessive protein in the body, with kidney failure. If that happens, have your doctor order a SERUM FreeLiteChain assay from any major lab, such as ARUP in Salt lake City. The test kit was developed by Bindings of the UK. Medicare pays for it. If the result is 1.6 mg/dL or higher, there is your major problem. Remember, this is SERUM, not Plasma. The seemingly tiny bits of protein measured will make a lot of doctors pooh-pooh the assay, but find a new doctor if they do. Also, have the doctor order a DNA survey from AlnylamAct.com Except for checking for hydration, the GFR is just a sign that something serious is going to get much worse.

Thank you for the information!