Kidney Failure Risk Factor: Age

Why is age used as a risk factor to predict your chances of reaching kidney failure?

You might think that older age would increase your chance of reaching kidney failure sooner than someone younger. But studies on large numbers of people with chronic kidney disease (CKD) have shown that younger age may predict a faster time to reaching kidney failure.

This may be due to having CKD starting at a younger age, so that kidney failure happens sooner in life. Or as people get older, they're more likely to die from another problem like heart disease before they ever have a chance to reach kidney failure.

Also, patients in certain studies were counted as having kidney failure only if they were on dialysis or had a kidney transplant. These patients may have been younger than older patients who did not get either of these treatments. Therefore, older patients with kidney failure may not have been counted.

But no matter our age, we need to take good care of our kidneys. Kidney failure can happen at any age.

How does older age affect my kidneys?

Aging is a normal and natural process that affects all parts of the body, including the kidneys. But over time, our kidneys change in the way they look and in the way they work. Just as we see wrinkles and age spots on our skin, so too do the kidneys show changes that can be seen with a microscope.

The kidneys have tiny filters called nephrons that clean all the blood in our body. We're born with about a million of these units in each kidney. But as we get older, we lose some nephrons, and some other nephrons might not work as well as when younger.

Loss of nephrons will affect the estimated glomerular filtration rate (eGFR), a blood test that shows our level of kidney function (how well our kidneys are working). Please note that a decline in kidney function is normal as we get older and may not always be a sign of kidney disease.

Having less nephrons and less kidney function makes it harder for the kidneys to handle stress. For example, diseases such as diabetes and high blood pressure place more stress on older kidneys. The effects of this stress are greater for older kidneys and can cause more kidney damage than in younger kidneys.

Older kidneys also have more chance to suffer from acute kidney injury (AKI). AKI is kidney damage that happens very quickly. It happens because of problems like using too high a dose of a certain drug, or not drinking enough fluid on a very hot day.

What can you do to protect your kidneys at any age?

  • Get your kidneys checked at least every year. Your healthcare team will do a simple blood test to find out your eGFR. They will also do a urine albumin-to-creatinine ratio (UACR), which shows if you have protein (albumin) in the urine. Protein in the urine may mean you have kidney damage.
  • Control blood pressure if you have high blood pressure.
  • Control blood sugar if you have diabetes.
  • In general, if you have CKD, avoid non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen.
  • If you have CKD, tell your healthcare team before having any test that uses contrast dye.
  • Do not smoke.
  • Exercise and follow a healthy diet that's low in sodium, saturated fat, and sugar, but high in fresh fruits, vegetables, whole grains, lean meats, fish, and poultry. Avoid highly processed foods.
  • Stay at a healthy weight. Lose weight if your healthcare team says that you should.
  • Discuss any vitamins, minerals, herbs, weight loss or body building supplements with your healthcare team before taking them. Many of these products can hurt your kidneys.
  • Make sure that any drugs you take are the right dose for your age and your level of kidney function. You should discuss this with your healthcare team.

For more information:

  • Speak with your healthcare team
  • Visit the National Kidney Foundation at