Most people don’t feel kidney disease until it’s too late. By the time symptoms like fatigue, swelling, or foamy urine show up, up to 70% of kidney function may already be gone. That’s why chronic kidney disease is called a silent killer - it creeps in without warning, and millions don’t know they have it. In the U.S., about 37 million adults have CKD, and 9 in 10 don’t know it. The same pattern holds in the UK. The good news? If caught early, progression can be slowed - even stopped - with the right steps.
What Chronic Kidney Disease Really Means
Chronic kidney disease isn’t just about kidneys working a little slower. It’s defined by lasting damage that’s been present for at least three months. This damage can come from high blood pressure, diabetes, inflammation, or even genetic conditions. The kidneys don’t just filter waste - they balance fluids, regulate blood pressure, make red blood cell-stimulating hormones, and keep bones strong. When they’re damaged, all these systems start to fail. The key is that CKD isn’t one disease. It’s a spectrum. Two people can have the same eGFR number but very different risks. That’s why modern diagnosis looks at two things: how well the kidneys filter blood (eGFR) and how much protein leaks into the urine (albuminuria).The Six Stages of CKD - Defined by Science
The current standard, set by KDIGO in 2012 and still used today, divides CKD into five stages based on eGFR (estimated glomerular filtration rate), plus three levels of albuminuria. Together, they paint a full picture of risk.- Stage G1 - eGFR 90 or higher. Kidneys look normal on tests, but there’s damage - protein in urine, structural issues, or scarring seen on scans. This stage is often missed because people feel fine.
- Stage G2 - eGFR 60-89. Mild reduction. Still no symptoms. But if albuminuria is high, this is where intervention starts.
- Stage G3a - eGFR 45-59. Mild to moderate loss. About 4% of adults in the U.S. are here. Many are diagnosed accidentally during a routine blood test.
- Stage G3b - eGFR 30-44. Moderate to severe loss. At this point, risk of heart disease and kidney failure jumps sharply. People in G3b are 2.6 times more likely to reach kidney failure within five years than those in G3a.
- Stage G4 - eGFR 15-29. Severe loss. Symptoms like nausea, itching, and swelling become common. Nephrologists get involved. Preparation for dialysis or transplant begins.
- Stage G5 - eGFR under 15, or on dialysis. Kidneys have failed. Without treatment, life isn’t sustainable. 98% of people here need dialysis or a transplant.
Albuminuria: The Silent Warning Sign
eGFR alone doesn’t tell the whole story. That’s why albuminuria - the amount of protein (albumin) leaking into urine - is just as important. It’s measured as uACR: urine albumin-to-creatinine ratio.- A1 - less than 3 mg/mmol. Normal or mildly increased. Low risk.
- A2 - 3 to 30 mg/mmol. Moderately increased. Signals early damage.
- A3 - over 30 mg/mmol. Severely increased. This is the red flag. People with A3 have more than five times the risk of dying from kidney or heart disease, even if their eGFR is still in the normal range.
How Fast Does CKD Progress?
Progression isn’t the same for everyone. For some, it’s slow - taking decades. For others, especially those with diabetes or uncontrolled high blood pressure, it can race forward. In Stage G3a, about 1 in 4 people will progress to G4 within five years - unless they take action. Medications like ACE inhibitors or ARBs can cut that risk by 37%. Lifestyle changes - lowering salt, controlling blood sugar, quitting smoking - also make a measurable difference. But here’s the catch: if you’re over 70 and your eGFR is 55, it might not be disease. It might just be aging. That’s why doctors now look at trends - not just single numbers. If your eGFR drops more than 5 points per year, that’s a red flag. If it’s stable for two years, it’s likely not progressive CKD.Early Detection: The Only Real Advantage
Most people with early-stage CKD have no symptoms. That’s why diagnosis often happens by accident - during a check-up for something else. One patient found out she had Stage G2 CKD because her doctor noticed protein in her urine before knee surgery. Another was diagnosed after routine blood work for high cholesterol. The NHS and CDC recommend testing for CKD if you have:- Diabetes
- High blood pressure
- Heart disease
- Family history of kidney failure
- Being over 60
- Being of African, South Asian, or Native American descent
Who Gets CKD - And Why
Diabetes causes nearly 4 out of 10 cases. High blood pressure causes about 1 in 4. Glomerulonephritis - inflammation of the kidney’s filters - accounts for another 1 in 10. But disparities are stark. African Americans are 3.5 times more likely to develop CKD than White Americans. Native Americans have the highest rates of diabetes-related kidney disease in the world - nearly half of those with diabetes develop kidney damage. In the UK, people of South Asian descent are twice as likely to need dialysis. Why? Genetics play a role, but so do access to care, diet, and delayed diagnosis. Many in these communities don’t get regular check-ups until symptoms are advanced. That’s why community screening programs - like the one in Baltimore that tested over 5,800 people and found over 1,200 undiagnosed cases - are so vital.
Bennett Ryynanen
December 31, 2025 AT 15:46Yo I got my eGFR checked last year after my doc noticed my BP was spiking. Turns out I was G3aA2. Thought I was fine 'cause I didn't feel sick. Holy shit, this post hit home. Started on an ACE inhibitor and cut the salt like my life depended on it. It does. Now I'm G3aA1 and my doc says I'm holding steady. Don't wait until you're dizzy and swollen.
Chandreson Chandreas
January 1, 2026 AT 06:54Bro, I’m from India and my uncle got dialysis at 52. He never got tested. Just thought fatigue was ‘work stress’. Now I make my whole family do urine tests every year. 💪🩸 One test. Two minutes. Could save your kidneys. Don’t be like us.
Darren Pearson
January 1, 2026 AT 09:27While the general sentiment of early detection is laudable, the conflation of age-related eGFR decline with pathological CKD remains methodologically unsound. The KDIGO guidelines themselves caution against overdiagnosis in the elderly without longitudinal data. To frame a 70-year-old with eGFR 55 as having 'disease' is a gross oversimplification that risks iatrogenic harm through unnecessary pharmacological intervention.
Stewart Smith
January 1, 2026 AT 11:03So… I’m G2A3 and I feel like a normal guy who just really likes tacos and naps. But apparently my kidneys are screaming? Weird. I guess I’ll start drinking water and stop pretending I’m 25. 🤷♂️
Retha Dungga
January 3, 2026 AT 04:04we are all just dust in the wind and our kidneys are just filters for the soul anyway why fight it maybe the universe wants us to slow down 🌌💧
Jenny Salmingo
January 4, 2026 AT 12:36I’m a nurse and I see this all the time. People think if they don’t feel bad, they’re fine. But kidneys don’t scream until it’s too late. Just ask your doc for the two simple tests. It’s free. It’s easy. It could save your life. No drama. Just do it.
Aaron Bales
January 5, 2026 AT 04:37Stage G3aA3 = high risk. Stop ignoring it. ACE inhibitors. SGLT2 inhibitors. Low sodium. No NSAIDs. Daily BP check. That’s your new routine. Not optional. Not ‘maybe’. Do it. Your future self will thank you.
Lawver Stanton
January 5, 2026 AT 08:55Okay but let’s be real - this whole CKD screening thing is just Big Pharma’s way to sell more pills. I mean, who even knows if all this ‘albuminuria’ crap matters? My grandma lived to 94 eating fried chicken and soda. She never heard of eGFR. Maybe we’re just overmedicalizing aging? And why does everyone act like a kidney is some sacred temple? It’s just a filter. I’ve got a coffee maker that’s more important than my kidneys.
Also, why is everyone suddenly so obsessed with urine tests? Are we turning into medical detectives now? ‘Oh honey, did you check your ACR this morning? No? Well I guess we’ll just wait until you start vomiting blood.’
And don’t even get me started on AI predicting kidney decline. I’m pretty sure my Fitbit knows more about my health than some algorithm trained on 27 variables. Also, who gave doctors the right to label me ‘G3aA3’ like I’m a wine rating? I’m not a bottle of Merlot.
Sara Stinnett
January 6, 2026 AT 05:34How quaint. You all treat CKD like it’s some tragic mystery waiting to be solved - when in reality, it’s just biology doing its job. The body doesn’t care about your ‘stages’ or your ‘ACR scores.’ It just decays. And if you’re too lazy to eat clean or take your meds, then maybe you deserve the consequences. This isn’t a ‘silent killer’ - it’s a silent consequence of poor choices. Stop pretending it’s a public health crisis and start owning your lifestyle.