Why Is Chronic Kidney Disease (CKD) on the Rise? 6 Things to Know

Chronic kidney disease (CKD) is a condition that affects an estimated 37 million American adults—or one in seven. And yet, many people don’t even know they have it.

That’s because CKD is a silent disease, progressing without symptoms as the kidneys gradually—and permanently—lose function over months or years. When people finally start to experience symptoms, such as itchy skin, an impaired ability to urinate, and unexplained weight loss, among others, it means the disease has reached an irreversible stage. At that point, they may have lost so much kidney function that they will need dialysis or a kidney transplant.

CKD is also on the rise. "Diabetes is the number one cause of kidney disease; so, because more patients have diabetes, we're seeing more kidney disease,” says Randy Luciano, MD, a Yale Medicine nephrologist. High blood pressure is the second leading cause, and that’s on the rise as well. (There are other causes, including obesity and, less commonly, polycystic kidney disease, a genetic condition marked by multiple cysts in the kidneys.)

Once you have CKD, it and the accompanying kidney damage cannot be reversed. However, diagnosing and treating CKD early may help stop it from advancing. There are new treatments in the past few years that have been described as “game-changing” for their ability to slow the progression of CKD for years and possibly even decades, Dr. Luciano says.

Below, Dr. Luciano answers common questions about chronic kidney disease.

Chronic kidney disease is the medical term used to describe the gradual loss of kidney function over a period of at least three months. Because of this, excess fluid and waste from the blood remain in the body and may cause other health problems, such as heart disease and stroke, in addition to kidney failure.

CKD can occur for a variety of reasons, but diabetes and high blood pressure are the two most common ones. If someone has diabetes, high blood sugar can clog and narrow the kidney’s tiny blood vessels, leading to kidney damage. In people with high blood pressure, there is an increase in the force of blood pushing against vessel walls throughout the body, including in the kidneys, affecting their ability to eliminate waste and extra fluid from the body—key kidney functions. Other issues that can lead to CKD include glomerulonephritis, an inflammation of the tiny filters in the kidneys; lupus nephritis, an autoimmune disease; polycystic kidney disease; and kidney cancer.

While anyone can develop CKD, some people are at higher risk.

Risk increases with age, with people over 65 most likely to be diagnosed with CKD. In addition to having diabetes (type 1 or 2) and high blood pressure, people are also at higher risk if they have heart disease, obesity, or past damage to the kidneys from an infection or surgery.

Family history matters, too. "If you have a family history of CKD, kidney failure, or inherited kidney disorders, you should talk to your provider about kidney health when you’re in your 20s,” Dr. Luciano says. “People with first-degree relatives affected by CKD are at higher risk, and those with other relatives who have the condition have an elevated risk as well. A young patient may not have CKD that will impact their life for the next 10 or 15 years, but we can take steps to lower their risk as they age.”

Race, ethnicity, and socioeconomic issues may play a role as well. As many as 20% of non-Hispanic Black adults in the U.S. are estimated to have CKD compared to 11.7% for non-Hispanic white adults, according to the CDC. “This is probably multifactorial,” says Dr. Luciano, adding that access to health care and affordable medications can be a factor in some cases. And minority populations are more likely to have diabetes, heart disease, high blood pressure, and obesity, all conditions that raise the risk for CKD, he says.

“We also know that some Black patients have certain genetic risks that may increase their chances of developing CKD,” Dr. Luciano says. A nephrologist can arrange genetic testing, which involves a tissue swab of the cheek or a blood draw the patient can perform at home. If a patient tests positive for a genetic mutation linked to CKD, “the goal is to be preemptive and manage diabetes or blood pressure using the latest medicines aggressively to get that disease under control,” he says.

CKD can be detected (and monitored) using two simple tests: a blood test and a urine test. The first is often done as part of a regular physical examination with routine bloodwork that includes a test called glomerular filtration rate (GFR)—the GFR score is based on the level of creatinine in a person’s blood, combined with their age and sex. (Creatinine is a waste product, resulting from the normal breakdown of muscle tissue and digestion of protein from food; too much of it in the blood is a sign that the kidneys are not cleaning out waste efficiently.)

The second test is a urinalysis to evaluate the urine for albumin, the main protein found in blood. Albumin in the urine is called albuminuria, and its presence is a sign that the kidneys are damaged.

There are five stages of kidney disease, which are determined by GFR scores that remain consistent for at least three months:

• Stage 1. GFR: 90 or higher. Stage 1 CKD means you have a normal GFR, but there is protein in your urine. The presence of protein alone means you are in Stage 1 CKD, even if there is no kidney damage.
• Stage 2. GFR: 60-89. This suggests mild kidney damage, but the kidneys still work well. Because most people don’t notice symptoms until Stage 3, this stage of CKD often goes unnoticed; however, if caught, it may still be possible to slow down the loss of kidney function with lifestyle changes.
• Stage 3. GFR: 30-59. This stage is divided into two subcategories: 3a, which is mild-to-moderate damage, with a GFR between 45 and 59, and 3b, which is moderate-to-severe damage, with a GFR between 30 and 44. At this stage, CKD can cause complications, such as anemia and bone disease. Although some people still may not have symptoms, many experience one or more of a range of symptoms, including feeling weak and tired, lower back pain, dry or itchy skin, urinating more or less than usual, or having foamy or darker-colored urine. Although at this point the kidneys are irreversibly damaged and don’t work as well as they should, with treatment and healthy life changes, many people in this stage do not move to Stage 4 or Stage 5.
• Stage 4. GFR: 15-29. This is the last stage before kidney failure, when damage is severe. The kidneys have a difficult time filtering out waste, which then builds up in the body where it can cause a variety of health problems, including heart disease and stroke. Patients and their providers should begin to plan for future dialysis or a kidney transplant.
• Stage 5. GFR: Less than 15. The kidneys are close to failure or have already failed, the latter of which is called end-stage CKD (ESKD). Symptoms of kidney failure may include some of the issues that some people start to experience in Stage 3, along with some new ones, such as rashes; foamy, frothy, or bubbly urine; feeling less hungry than normal; and feeling sick in the stomach and throwing up. This stage calls for dialysis or a kidney transplant to keep patients alive.

Treatment usually depends on the underlying cause of kidney disease. “Not all chronic kidney disease progresses in the same way,” Dr. Luciano says. For instance, “if we know a patient’s kidney disease is due to diabetes, we focus on treating that,” he says, because improving diabetes will slow further damage. Likewise, patients with high blood pressure must get their blood pressure under control, whether that includes making lifestyle changes or taking medication.

In the past few years, several relatively new CKD medications have become available. Some of these are also used to treat diabetes and other CKD-related conditions, including obesity and heart disease. These drugs include:

• SGLT-2 inhibitors (also called flozins). These include several medicines, available as pills, that are used in diabetes treatment. Several, including empagliflozin (Jardiance®), are FDA-approved for CKD. One way these medicines work is by preventing the kidneys from reabsorbing blood sugar; the glucose instead goes to the urine and is eliminated from the body, thereby protecting the kidneys.
• Finerenone (Kerendia®). This is an FDA-approved pill aimed at reducing the risk of kidney function decline and failure, as well as serious heart conditions and events associated with type 2 diabetes. It works by blocking proteins called MRs that can become overactivated in type 2 diabetes, leading to kidney inflammation and scarring.
• GLP-1 receptor agonists (glucagon-like peptide-1 receptor agonists). These include drugs that are FDA-approved for type 2 diabetes and may help people lose weight. One is semaglutide (Ozempic®), which is approved for weight loss under the brand name Wegovy®. These drugs have shown promise in reducing the risk of kidney failure, although they are not FDA-approved for that purpose at this time.

High blood pressure can be both a cause and a result of CKD, so blood pressure medications are often prescribed—and were used to treat CKD for decades before the newer drugs became available. These include ACE inhibitors (angiotensin receptor blockers) and ARBs (angiotensin-converting enzymes). They help blood vessels relax, so the blood can flow smoothly, preserving kidney function.

A series of other medications may also help. For instance, because poor kidney function can weaken bones, calcium and vitamin D supplements may be prescribed to keep them strong. Diuretics, which can help kidneys eliminate salt and water and facilitate urination, may be used to reduce swelling. And iron supplements can help address anemia.

It may also be important to stop taking certain medicines that can worsen kidney damage, such as NSAIDs (nonsteroidal anti-inflammatory drugs) and some arthritis medicines.

It depends. Having CKD doesn’t always mean the disease will progress to ESKD and require dialysis or a kidney transplant. “As kidney specialists, we try to establish the cause of the disease, treat it, and determine if a patient will require dialysis in the future,” Dr. Luciano says. “Sometimes, the last part is difficult because we don't know how they're going to respond to treatment, how their kidney disease is going to progress over time, and what other circumstances can develop in their life that can impact the disease.”

If, however, you progress to ESKD and your kidneys fail, you will need either dialysis or a kidney transplant to replace the work of the kidneys.

Out of almost 808,000 people in the U.S. who have ESKD, 69% are on dialysis, which was once done only in a health care setting. Now, many people choose types of dialysis that can be performed at home.

There are two types of dialysis treatment, both of which involve several treatments a week.

• Peritoneal dialysis: In a surgical procedure, a catheter (or plastic tube) is placed in the patient's belly. The patient hooks up a plastic bag of cleansing fluid to the tube, which transports the fluid to the abdomen, and is then used to drain it. Treatment can be continuous, as the person goes about their normal activities, or automated, in which the cleansing fluid is delivered and drained while the person sleeps.
• Hemodialysis: Blood is pumped out of the body through a tube and into an artificial kidney machine, which removes the waste and extra fluid before it’s sent back to the body. This is done three or four times a week, often in a health care setting, but it can sometimes be done at home.

“For those who can do it, we often recommend home dialysis,” Dr. Luciano says. “It tends to be easier for people, gives them more flexibility with their schedule, and is gentler on the body.”

Still, a kidney transplant is often the best solution—preferably before a patient reaches the point of requiring dialysis, Dr. Luciano says. That’s because while dialysis can take over the function of cleaning waste and excess water from the body, treatments can be time-consuming and cause such side effects as skin infections, low blood pressure, muscle cramps, weakness, and fatigue. It can also have a major impact on a person’s life, both emotionally and physically.

“The hope is that some of the newer medications will allow patients to stay on the waiting list longer without needing dialysis,” Dr. Luciano says.

In 2020, the remaining 31% of the almost 808,000 people in the U.S. with ESKD had kidney transplants, according to the CDC. People wait three to five years, more or less, for an organ from a deceased donor, depending on such factors as geographic location and blood type. “But if you have a living donor—either someone you know or a stranger willing to donate a kidney—and everything works out, you may get a kidney within three to six months,” Dr. Luciano says.

There are also kidney registries that can help match people with a living donor who is not a relative.

The best thing to protect your kidneys is to regularly see your primary care provider and, if relevant, share any family history of kidney disease or dialysis, Dr. Luciano says.

“If you have a yearly physical and bloodwork every two or three years, you’ll be much less likely to miss CKD,” he says. If there is an abnormality, such as an elevated level of creatinine, he recommends repeating the bloodwork once a year. “Your doctor may notice over time that your creatinine is a little off, which will trigger the follow-up appointment with a kidney specialist who can look into it more carefully.”

For anyone with diabetes, high blood pressure, or heart disease, and/or who is 65 or older, it’s especially important to talk to a doctor about CKD risk. People who are young and healthy but have a first-degree relative with a history of kidney disease or dialysis should consider being screened, Dr. Luciano says. “Chances are they're not going to have a serious case of CKD at an early age. But it's always good to make sure that we're not missing anything that would put them at risk as they age.”

As with many diseases, preventing a serious condition from developing also comes down to good general health, he says. This includes eating a diet rich in fruits and vegetables and low in salt, fat, and sugar; drinking enough water; being active for at least 30 minutes most days; sleeping seven to eight hours each night; avoiding smoking; and minimizing alcohol intake.

“There are some people who are going to develop kidney disease no matter what they do, just as there are people who will develop heart disease,” Dr. Luciano says. “But good general care can mean early diagnosis and treatment, which can keep people healthy.”