Kidney disease is extremely common. Globally, about 788 million adults are living with chronic kidney disease (CKD), which translates to roughly 14% of the adult population. In the United States alone, more than 1 in 7 adults, or about 35.5 million people, have some form of CKD.
What makes these numbers especially striking is how few people know they’re affected. As many as 9 in 10 Americans with CKD are unaware they have it, largely because early-stage kidney disease causes no noticeable symptoms.
How Kidney Disease Is Measured
CKD is defined by how well your kidneys filter waste from your blood. Doctors measure this with a blood test that estimates your glomerular filtration rate (eGFR), essentially a score that reflects your kidney function as a percentage of what’s considered normal for a healthy young adult. An eGFR of 90 or above is normal. Below 60 signals meaningful kidney damage, and below 15 means kidney failure.
A urine test for albumin, a protein that healthy kidneys keep in your blood, is the other key marker. When albumin leaks into urine, it’s a sign that the kidneys’ filtering units are damaged. Together, these two numbers determine whether you have CKD and how advanced it is, placing you in one of five stages.
Prevalence by Stage
Not all kidney disease is the same, and the vast majority of cases are mild. The breakdown by stage looks like this:
- Stage 1 (normal filtration, but signs of damage): 3.5% of the population
- Stage 2 (mildly reduced function): 3.9%
- Stage 3 (moderately reduced function): 7.6%
- Stage 4 (severely reduced function): 0.4%
- Stage 5 (kidney failure): 0.1%
Stage 3 is by far the most commonly diagnosed, partly because stages 1 and 2 rarely produce symptoms and often go undetected. Most people diagnosed with stage 3 CKD will never progress to kidney failure, especially if they manage the underlying causes. Still, even mild CKD raises the risk of heart disease and other complications, which is why catching it matters.
Most People Don’t Know They Have It
The awareness gap around kidney disease is enormous. The CDC estimates that 9 out of 10 Americans with CKD don’t know they have it. Even among people with severely reduced kidney function who aren’t yet on dialysis, 40% are unaware of their condition.
This happens because CKD is silent in its early and middle stages. Your kidneys can lose a significant amount of function before you feel anything at all. Symptoms like fatigue, swelling in the ankles, foamy urine, or difficulty concentrating typically don’t appear until the disease is advanced. Routine blood and urine tests are the only reliable way to detect it early, but kidney screening isn’t part of standard checkups for most people unless they have known risk factors.
Who Is Most at Risk
Diabetes and high blood pressure are the two leading drivers of kidney disease, and the numbers reflect that clearly. About 1 in 3 people with diabetes and 1 in 5 people with high blood pressure have CKD. Since these conditions are themselves widespread (more than 130 million Americans have one or both), they account for a large share of kidney disease cases overall.
Age is another major factor. Kidney function naturally declines over time, and CKD is far more prevalent in older adults. Other risk factors include a family history of kidney disease, obesity, heart disease, and a history of acute kidney injury. Smoking and frequent use of certain over-the-counter painkillers (particularly NSAIDs like ibuprofen) can also contribute to kidney damage over time.
When Kidney Disease Becomes Kidney Failure
A small but significant number of people with CKD eventually reach stage 5, where their kidneys can no longer sustain life without intervention. In the United States, about 815,900 people were living with end-stage kidney disease in 2022. Of those, roughly 58% were on dialysis and 32% had a functioning kidney transplant.
That number has nearly doubled since 2002, when about 429,000 Americans had end-stage kidney disease. The growth reflects both the rising prevalence of diabetes and hypertension and the fact that people on dialysis and transplant recipients are living longer than they used to. The trajectory did flatten briefly in 2020, likely due to excess mortality during the pandemic, but has resumed a slow climb since.
Why These Numbers Keep Growing
Kidney disease prevalence has been rising steadily for decades, driven largely by the global increase in diabetes, high blood pressure, and obesity. These conditions damage the small blood vessels in the kidneys over years, and as populations age and metabolic disease becomes more common, more people are developing CKD as a downstream consequence.
Improved detection also plays a role. As more health systems adopt routine kidney screening for high-risk groups, cases that would have gone unnoticed a generation ago are now being identified. This is, in many ways, a good thing: CKD caught at stage 2 or 3 can often be slowed or stabilized with blood pressure control, blood sugar management, dietary changes, and newer medications that protect kidney function. The challenge is closing the awareness gap so that more of those 788 million people worldwide actually know they’re affected and can act on it before the disease progresses.