People with severe kidney disease can develop confusion, along with other cognitive symptoms.

Your kidneys act as a filter for your blood. They remove waste and help keep levels of water and minerals at their proper levels.

Renal failure is when your kidney function drops below 15% of its normal value and your kidneys can no longer filter your blood adequately. Renal failure is also called:

People with severe kidney disease can develop cognitive symptoms like confusion or problems concentrating. These cognitive changes can develop for different reasons, such as damage to the small blood vessels in your brain or due to the buildup of waste products in your blood.

In this article, we look at why renal failure causes confusion and how it’s managed.

Cognitive impairment can range from mild to severe in people with chronic kidney disease.

Severe impairment that impacts your daily life is referred to as dementia, which is thought to be irreversible. Confusion is medically known as delirium, a short-term change in mental status caused by something outside of the brain.

Cognitive impairment is estimated to affect 10% to 40% of people with chronic kidney disease.

Kidney failure and cognitive impairment are both common in aging adults, but 2021 research suggests that people with kidney disease that has advanced to the point they need dialysis develop cognitive impairment up to 3 times more often and at a younger age.

Kidney disease can affect your ability to think in many ways. Here are some of the ways it may cause confusion.

Cerebrovascular disease

People with renal failure are significantly more likely than people in the general population to develop cerebrovascular disease.

Cerebrovascular disease is a group of conditions that cause problems with blood flow to your brain. It includes strokes and aneurysms.

Symptoms depend on what part of your brain is affected but can include:

Uremic encephalopathy

People with severe kidney disease may develop uremic encephalopathy. This condition is characterized by partially reversible neurological symptoms that occur due to the buildup of toxic substances in the blood. More than 130 different chemicals have been identified as potentially toxic.

Symptoms can range from mild to severe. They can include:


Dialysis, a form of treatment for kidney disease, can also potentially contribute to cognitive problems. Confusion is commonly observed in people undergoing dialysis and has been attributed to an electrolyte imbalance.

Learn more about dialysis below.

Cognitive symptoms caused by renal failure often seem to improve if treatment is started with dialysis or a kidney transplant. The initiation of dialysis can clear toxic chemicals from your blood and may reverse symptoms of uremic encephalopathy.

Confusion may not be reversible if it’s caused by another condition. For example, damage to the brain may be permanent if renal failure contributed to the development of a stroke.

If renal failure is severe and you or your loved one are near the end of life, sedatives may be used to manage confusion.

Other symptoms of renal failure can include:

Renal failure can be managed with either dialysis or a kidney transplant.


Dialysis is a treatment where a machine takes over the function of your kidneys. It involves removing fluid and waste from your blood and restoring your mineral levels.

Two main types of dialysis are used:

  • Hemodialysis: Your blood is filtered through an artificial kidney and returned to your body. You’ll have two needles inserted into your arm each connected to a tube that allows blood to flow to and from the artificial kidney.
  • Peritoneal dialysis: A tube called a catheter is inserted into your abdomen and a cleansing solution flows through. The lining around the organs in your abdomen, called the peritoneum, acts as a filter to remove waste from your blood. The cleansing solution is drained out with the substances that would have been filtered by your kidneys.

Hemodialysis is usually carried out 3 times per week at treatment centers with each session lasting about 4 hours. It can also be done at home, potentially overnight.

Peritoneal dialysis fluid usually needs to be repeated about 4 times per day and each session lasts about 30 to 40 minutes.

Kidney transplant

A kidney transplant is the only potential cure for renal failure. It involves replacing one of your two kidneys with a kidney from a donor. The donor might be a living person such as a family member or a deceased person.

At a certain point, it may not be possible to cure kidney disease or you may choose to stop treatment. Hospice care can help you alleviate the pain of chronic kidney disease and help you manage other symptoms as comfortably as possible.

Typically, hospice care is an option if your doctor believes you have less than 6 months to live or if you decide to stop dialysis treatment.

Renal failure can cause many symptoms including confusion or trouble concentrating. Cognitive symptoms of renal failure tend to get worse as kidney disease progresses.

Treating chronic kidney disease with dialysis or a kidney transplant is thought to at least partially reverse cognitive symptoms caused by the buildup of toxic chemicals in your blood.