Kidney disease is far more common than most people realize. Globally, about 788 million adults are living with some form of chronic kidney disease (CKD), which translates to roughly 14% of the adult population. In the United States alone, more than 35.5 million adults have CKD, and as many as 9 in 10 of them don’t know it.
How Many People Have Kidney Disease
The number of people with CKD worldwide has more than doubled since 1990, when an estimated 378 million adults were affected. By 2023, that figure had climbed to 788 million. In the U.S., the CDC estimates that more than 1 in 7 adults, about 14%, have some degree of chronic kidney disease.
Not all of those cases are severe. CKD is classified into five stages based on how well the kidneys filter waste from the blood. Most people with kidney disease are in the earlier, milder stages. The breakdown looks roughly like this:
- Stage 1 (mild damage, normal function): 3.5% of the population
- Stage 2 (mild loss of function): 3.9%
- Stage 3 (moderate loss of function): 7.6%
- Stage 4 (severe loss of function): 0.4%
- Stage 5 (kidney failure): 0.1%
Stage 5, also called end-stage kidney disease, is what most people mean when they say “kidney failure.” At this point the kidneys can no longer sustain life on their own, and a person needs dialysis or a transplant to survive. Nearly 750,000 people in the U.S. and an estimated 2 million worldwide are living with kidney failure at any given time.
Why So Many Cases Go Undetected
One of the most striking facts about kidney disease is how quietly it progresses. The kidneys can lose a significant amount of function before a person feels any symptoms at all. The CDC estimates that up to 9 in 10 U.S. adults with CKD are unaware of their condition. Among those specifically in stage 3, where kidney function has already dropped to a moderate level, research from population studies has found that over 98% had no idea they were affected.
This matters because early-stage kidney disease is far easier to slow or stabilize than advanced disease. Without routine blood and urine tests, most people don’t discover a problem until their kidneys are already significantly damaged. By that point, the progression toward kidney failure becomes harder to reverse.
What Causes Kidney Failure
Two conditions account for the vast majority of kidney failure cases. Diabetes is the leading cause, responsible for about 47% of new cases in the U.S. High blood sugar gradually damages the tiny blood vessels inside the kidneys that do the actual filtering work. High blood pressure is the second leading cause, accounting for roughly 29% of new cases. It damages those same delicate vessels through sustained force over years or decades.
Together, diabetes and high blood pressure explain about three-quarters of all new kidney failure diagnoses. The remaining quarter includes a mix of conditions: autoimmune diseases that attack the kidneys, inherited conditions like polycystic kidney disease, repeated kidney infections, and prolonged use of certain medications that are toxic to kidney tissue. Rising rates of obesity, sedentary lifestyles, and diets high in processed food are driving increases in both diabetes and high blood pressure, which in turn are expected to push CKD numbers even higher in the coming years.
Who Is Most at Risk
Kidney failure does not affect all populations equally. Black Americans face three to four times the risk of developing kidney failure compared to white Americans. While Black individuals make up about 13% of the U.S. population, they account for roughly 32% of all kidney failure cases. This disparity is driven by a combination of factors: higher rates of diabetes and high blood pressure, genetic variants that affect kidney filtration, and longstanding inequities in access to preventive care and early treatment.
Age is another major factor. Kidney function naturally declines with age, and the risk of progressing to kidney failure rises substantially after 60. People with a family history of kidney disease, those who are obese, and smokers also face elevated risk. Alcohol consumption adds to the burden as well, with global per-capita alcohol intake projected to keep climbing through the end of this decade.
The Transplant Shortage
For people who reach kidney failure, the options are dialysis or a transplant. Dialysis keeps a person alive by mechanically filtering the blood, typically three times a week for several hours per session. A transplant offers a better quality of life and longer survival, but the gap between supply and demand is enormous. More than 100,000 patients in the U.S. are currently on the kidney transplant waiting list, yet only about 21,000 donor organs become available each year. Most people with kidney failure will spend years on dialysis before receiving a transplant, and many never receive one at all.
The Cost of Kidney Failure
Kidney failure places an outsized burden on the healthcare system. The roughly 750,000 Americans living with end-stage kidney disease represent just 1% of the Medicare population, yet they account for about 6% of the entire Medicare budget. Total Medicare spending on these patients reached $37.1 billion in 2020. The high cost reflects the intensity of treatment: dialysis is expensive, transplant surgery and lifelong anti-rejection medications are expensive, and people with kidney failure frequently have multiple other serious health conditions that require ongoing care.
That financial weight is part of why public health agencies have pushed for earlier detection and better management of the conditions that lead to kidney failure in the first place. Controlling blood sugar, managing blood pressure, and catching kidney damage early through simple lab tests are the most effective ways to keep CKD from progressing to the point where dialysis or a transplant becomes necessary.