Medically Approved

Could you have chronic kidney disease and not know it?

Doctor talking to patient

Symptoms such as fatigue and leg swelling could be early signs of kidney disease. Here’s how to tell if you’re at risk — and what you can do about it.

Hallie Levine

By Hallie Levine

Here’s a sobering fact: 9 in 10 people with chronic kidney disease (CKD) aren’t aware they have it, according to the National Institutes of Health (NIH).

“Most patients don’t develop signs of the disease until it’s fairly advanced,” says Staci Leisman, MD. She’s a kidney specialist at Mount Sinai Hospital in New York City. By the time symptoms emerge, the kidneys may have become severely damaged.

This is troubling, because your kidneys play an important role in your health. The 2 bean-shaped organs keep your blood healthy by filtering out excess fluid, minerals and waste products. They refine about half a cup of blood every minute, according to the NIH. And much of the waste they pull out is expelled as urine.

Given the importance of your kidneys, Dr. Leisman and other medical professionals want you to take their health seriously. Here’s a closer look at CKD: who is most at risk, what to look for, how to catch a kidney problem early and what you can expect from treatment.

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Who’s at risk for chronic kidney disease?

While anyone can develop a kidney problem, there are a few risk factors that raise your chances, says David S. Goldfarb, MD. He’s the clinical chief of nephrology at NYU Langone Health in New York City. As he explains, you may be more at risk if you have any of these conditions:

Diabetes. This is the No. 1 cause of kidney disease. About 1 in 3 adults with diabetes have kidney disease, according to the NIH. And high blood sugar, a defining feature of diabetes, is a direct cause. It injures the small blood vessels in your body, including those in your kidneys. As a result, your kidneys can’t properly filter your blood.

High blood pressure. As with blood sugar, high blood pressure can also hurt your kidneys’ ability to do their job. “Prolonged high blood pressure can lead to narrowing of the blood vessels, which eventually damages them,” explains Dr. Leisman. “Since your kidneys’ blood vessels no longer work properly, your kidneys have a harder job removing waste and fluid from your body.”

Glomerulonephritis. This is a group of diseases that damage nephrons, structures in your kidneys that filter blood and produce urine. When nephrons are damaged, they can’t filter your blood properly.

The National Kidney Foundation (NKF) recognizes 2 kinds of glomerulonephritis: acute and chronic. Acute can come on quickly after a bacterial infection such as strep throat. Chronic glomerulonephritis, on the other hand, comes on gradually. It can be genetic, or it can be caused by an autoimmune disease such as lupus.

Polycystic kidney disease. This is a genetic disorder that happens when cysts, or fluid-filled sacs, develop in your kidneys. This makes it hard to filter waste properly. Polycystic kidney disease is responsible for about 5% of kidney failures, says the NKF.

Common signs of kidney failure

The symptoms below don’t mean that you have kidney disease for sure. But you might. So if you experience them, talk to your doctor.

Swelling. When your kidneys are damaged, they’re not able to filter out salt as well as before, says Dr. Goldfarb. That can lead to fluid retention and edema, or swelling in your ankles, feet and legs. (Learn more about edema here.)

Loss of appetite. If you find yourself suddenly eating less than you used to, that could indicate that toxins are building up in your body. This could be a sign that your kidneys aren’t filtering the way they should, says Dr. Goldfarb.

Excessive nighttime peeing. If you’ve collected fluid in your legs and ankles during the day, it can flow straight to your kidneys when you lie down to sleep, according to the NKF. That can result in repeated trips to the bathroom. (Nighttime urination could also be a sign of prostate trouble.)

Fatigue. In addition to filtering waste, healthy kidneys make a hormone called erythropoietin (EPO), which tells your bone marrow to make red blood cells. If your kidneys aren’t working as well as they should, they won’t make enough of this important hormone, explains Dr. Leisman. As a result, you produce fewer red blood cells, which could lead to a condition called anemia.

Bloody or foamy urine. White foam indicates unusually high levels of a protein called albumin. Normally, this protein appears only in small amounts in urine, says Dr. Leisman. But with kidney disease, levels could spike.

Meanwhile, if you see blood in your urine, that means you’re passing red blood cells that should still be inside your body. “When your kidneys are healthy, their filters actually prevent blood from entering your urine,” explains Dr. Leisman.

Blood in urine could also be caused by a UTI (urinary tract infection) or kidney stone. But in any case, you’ll want to be checked out by a doctor. (This guide can help you decode changes in your urine.)

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How to catch a kidney problem early

The NKF recommends talking to your doctor about routine screening for kidney disease if any of the following apply:

  • You have diabetes
  • You have high blood pressure
  • You’re 60 or older
  • You have a family history of kidney failure

To check for kidney disease, your doctor will run 2 tests:

  • GFR (glomerular filtration rate), a blood test that checks how well your kidneys are filtering your blood
  • A urine test to check for elevated levels of the protein albumin


“When people learn that they have chronic kidney disease, they automatically assume they’ll need dialysis,” says Dr. Goldfarb. But that’s not necessarily the case. “With proper treatment, they can manage this disease for years,” he says. Your treatment plan may include:

Blood pressure medications. Most people with CKD also have high blood pressure, says Dr. Goldfarb. So taking medication for kidney and heart health is critical. “This is probably the most important part of treatment for people with CKD,” he says.

A study published in Nature found that when people with CKD reduced their systolic blood pressure (the top number) to less than 130, the risk of disease progression fell by 42%.

Two classes of blood pressure medications have been shown to lower both blood pressure and levels of protein in the urine. They’re called angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB).

Your doctor may also add a diuretic (water pill) to try to further lower your blood pressure (and expel excess potassium).

Related reading: What to eat (and avoid) when you’re taking diuretics.

Dietary changes. The most important food habit is to restrict sodium to help control blood pressure, says Dr. Leisman. Your doctor may also want you to follow a lower-protein diet and limit foods high in either potassium or phosphorus. (Read more about what to eat when you have kidney disease.) 

Medications to control your blood sugar if you have diabetes. Managing blood sugar can improve the health of blood vessels in your kidneys. To this end, the NIH recommends that you regularly test your glucose, or blood sugar.

A class of medications called glucose cotransporter 2 (SGLT-2) inhibitors have also shown potential to help slow CKD when used alongside other blood pressure medications. (Read more about SGLT-2 medication.)

Following these precautions can have a big impact, but if they don’t work, your kidney disease could progress into kidney failure. In that case, you’ll require dialysis or a kidney transplant. But the odds are in your favor: While about 37 million Americans live with chronic kidney disease, only around 786,000 — roughly 2% — have kidney failure.

“For most people with kidney disease, the risk of heart attack or stroke is greater than the risk that they will eventually need dialysis or a kidney transplant,” says Dr. Goldfarb. “But that’s also why it’s so important to get related conditions under control.”

Optum Perks can help you with your treatment. Download our discount card, and when it comes time to purchase medication, you could save up to 80% at the pharmacy. Just present the card at checkout.


Additional sources
Chronic kidney disease statistics: National Institutes of Health
Kidney overview: National Institutes of Health
Diabetes and kidney disease: National Institutes of Health
High Blood Pressure and Kidney Disease: National Institutes of Health
Glomerulonephritis overview: National Kidney Foundation
Polycystic Kidney Disease: National Kidney Foundation
Reducing blood pressure reduces CKD progression: Nature (2021). “Association of blood pressure and renal outcome in patients with chronic kidney disease: a post hoc analysis of FROM-J study
Managing chronic kidney disease: National Institutes of Health