Understanding GFR and the 5 stages of CKD

In the summer of 2023, my endocrinologist noticed something in my blood work. Not a crisis, but a signal. The kind of thing a doctor catches early and notes in the chart as something to continue to monitor.

He watched. And over the next several months, what he was watching got worse.

I was already a 3-for-3 on the risk factors for kidney failure: diabetes, high blood pressure, and some hereditary genes that had not done me any favors. A few scans confirmed cysts on my kidneys, which on their own are not uncommon. But paired with everything else, the picture was becoming clearer, even if I was not ready to look at it.

Eventually, he referred me to a kidney specialist, a nephrologist. I sat across from her, watching her circle a number on my lab sheet. At the time, I did not have a basis for the number or what it should have been.

And that is when I started hearing a new acronym talked about regularly. My GFR.

What GFR is:

stock image of blurred blood test results

She slid the lab sheet across the desk and pointed to the number. I nodded as if I understood or remembered. I did not. After all, I hadn’t sat in my high school’s health class for a “few years.” That night, I typed “GFR” into a search bar and learned that it stands for glomerular filtration rate, a measure of how much blood your kidneys filter per minute. Healthy kidneys GFR ‘score’ is above 90. The higher the number, the better. The lower the number, the closer you are to a conversation no one is ready to have.

My nephrologist and I met regularly to track mine. I watched it. She watched it. We both could see where it was heading and discussed what each result meant, one at a time.

The thing about GFR that took me a while to understand: one number does not tell the whole story. The direction does. A GFR that is holding steady at 45 is a very different conversation than one that was 62 twelve months ago and is now at 45. The number is a snapshot. The trend is the story I was not prepared for.

I couldn’t fight the inevitable. My kidneys were failing me, just as my pancreas had in ’04.

As my GFR was quickly decreasing, my kidney failure stages were increasing; both were moving in the wrong direction.

The five stages, from my “I’m not a doctor and I don’t play one on TV,” understanding:

CKD is organized into five stages based on GFR. When I first saw this laid out, my immediate reaction was to find where I was on the list and then dread everything below it. That is a natural response. It is also not a useful one.

Here is what the stages mean for the person living in them.

Stage 1: GFR 90+
Damage is present, but function is near-normal. The kidneys are still showing up.
Stage 2: GFR 60–89
Mildly reduced function. This is the stage where monitoring matters most, because there is nothing yet to make you take it seriously.
Stage 3a: GFR 45–59
Moderately reduced. This is often when a nephrologist enters the scene, and the words “chronic kidney disease” are said directly to you for the first time, not just referenced in lab notes.
Stage 3b: GFR 30–44
Where things become real. And scary. I sat in appointments thinking, aren’t I too young for this? Come to find out, people of end-stage ages have end-stage renal disease (ESRD). That was not the answer I was looking for, but it was the truth.
Stage 4: GFR 15–29 (The last GFR I clearly remember was 16, and 46 stands out as likely where this all started.)
Severely reduced kidney function. Planning for kidney dialysis and/or transplant begins. A team that plans is a team making sure you are never caught without options.
Stage 5: GFR <15
Kidney failure. Treatment is required to sustain life. I eventually sat through a workshop where, at some point, the voices kept going, but my brain had stopped taking notes. The diagrams on the presenter’s screen, the handouts on the table, the options laid out one after another (peritoneal dialysis, hemodialysis, deceased donor, living donor) all blurred into a single overwhelming fact: there was no perfect answer. Dialysis sustains, and a transplant is the best treatment, but that means someone donating their kidney to me, either deceased or living.

How fast does GFR usually decline?

For most people with CKD, the decline is slow, measured in years and sometimes decades. On average, GFR may drop one to two points per year. But averages do not tell individual stories.

Some people plateau. Some progress faster, especially when blood pressure runs high, blood sugar stays uncontrolled, and inflammation is active in the kidneys. This is why the labs keep coming. Your nephrologist is not just collecting data. They are watching the slope of the line between visits.

What can slow the slope? Controlling blood pressure. Managing blood sugar. Watching certain medications that put an extra strain on the kidneys. Being thoughtful about protein and sodium. Avoiding certain foods. None of it is exciting, but all of it matters.

I will not pretend that doing all the right things guarantees a different outcome. My kidneys kept declining despite my best efforts, because that is sometimes how this goes. What I can tell you is that understanding the numbers, watching the trends, and staying engaged in my own care gave me something important: I was never blindsided by what came next.

Saying it out loud:

From June until October, I held all of it internally before I was ready to speak any of it out loud. The night I finally told my family, I remember sitting there searching for the right words and finding none. What came out instead was the plain truth.

“Once I spoke it, it was real. And I wasn’t ready for it to be real.”

I got serious after telling family and friends as I prepared for the best treatment or treatments available. My mom attended that workshop with me. I learned as much as my brain was willing to retain.

I started peritoneal dialysis on April 15, 2024. With dialysis, they did not monitor GFR; at that point, they monitored how adequately the dialysis solution was helping me. I started dialysis for 6 hours a night and moved to 9 hours over the span of 18 months. While dialysis was sustaining me, I was still getting worse.

There is a particular kind of tired that comes from waking up every morning still tethered to a machine, still waiting, still not well enough, and extremely tired. The waiting list for a deceased donor runs three years or more. You qualify the day you start dialysis, even before you are accepted as a transplant candidate. I knew the math. I did it often.

My only hope for a somewhat normal life was a kidney transplant, and the best version of that hope was a living donor. I was accepted as a transplant candidate at UNMC in May of 2025, and on October 22, 2025, thanks to Jeff, a cross-match that worked from a donor I don’t know, their kidney became my life-sustaining kidney.

More than 100,000 people are waiting for a kidney donor. Be sure you have indicated your willingness to donate on your driver’s license and consider donating a kidney; the need is real and the need is great.