“There are a variety of symptoms caused by COVID-19. When you think of COVID-19 symptoms, you probably don’t think of the pain in the kidneys.”

This condition is not associated with the pain of the kidneys.

We know a lot about COVID-19 and the kidneys, so keep reading.

Kidney pain is typically described as a feeling of discomfort in the back and sides of your upper abdomen. Pain in this region is referred to as flank pain. It’s felt in the area that’s below your ribs and above your hips and pelvis.

The pain is worse on one side of the body.

COVID-19 can damage the kidneys. However, kidney pain is typically not a symptom of kidney damage. In fact, many people with kidney damage may not even know it’s occurred.

More often, kidney pain is caused by conditions like:

A blood clot in the kidney may also cause kidney pain and COVID-19 does increase the risk of blood clots.

It’s also possible that you can have COVID-19 and feel pain in the area of your kidneys that isn’t actually coming from your kidneys. There are some case studies reporting flank pain in people with COVID-19 that’s due to the infection actually affecting the lower part of their lungs.

Many of the reports of kidney involvement in COVID-19 are of acute kidney injury (AKI). This is when your kidneys suddenly stop working as they should.

In some situations, AKI causes no symptoms and is only detected during testing for other health conditions. In this case, tests typically pick up on increased levels of protein, blood, or both in the urine.

Symptoms of AKI can include:

AKI is serious and needs to be treated in a hospital with supportive care and, in some cases, dialysis. Dialysis helps to remove waste products and extra fluids from your blood when your kidneys have stopped working properly.

A 2021 study reported 1,835 people with AKI due to COVID-19. Of these individuals, 347 (19 percent) required treatment with dialysis.

Developing AKI when you have COVID-19 is associated with a poorer outcome. Another 2021 study of people hospitalized with COVID-19 found that AKI was associated with a significantly higher risk of death.

How does COVID-19 damage the kidneys?

Researchers are trying to figure out how the virus that causes COVID-19 damages the kidneys. It is possible that one or a combination of the mechanisms are at play.

  • direct infection: Some cells in the kidneys express the receptor protein, ACE2, that SARS-CoV-2 needs to enter a host cell. Because of this, it’s possible that the virus could be directly infecting and killing these cells.
  • immune activity: Some people with COVID-19 have high levels of cytokines, pro-inflammatory proteins made by the immune system in response to infection. High inflammation in the body may cause damage to kidney tissue.
  • blood clots: COVID-19 can increase the risk of blood clots. These clots may clog small blood vessels in the kidneys. This can block blood flow and lead to kidney damage.
  • low oxygen: Pneumonia due to COVID-19 can mean that less oxygen is entering your blood than usual. Low oxygen levels can cause many organs and tissues, including the kidneys, to not function properly.

It’s also possible that some drugs that are used to treat COVID-19 in people who are seriously ill, may contribute to kidney damage. Examples of these drugs include the antiviral drug remdesivir and certain antibiotics used to treat secondary bacterial infections.

There are a lot of problems with the kidneys after severe COVID-19. The exact prevalence can vary by study.

Studies have documented AKI in 36.6 percent to 46 percent of people hospitalized with COVID-19. The prevalence of AKI in those admitted to the intensive care unit (ICU) for COVID-19 can be even higher, up to 78 percent.

A 2021 review analyzed AKI prevalence in COVID-19 and included 54 studies. The overall prevalence of AKI in people hospitalized with COVID-19 was 28 percent, rising to 46 percent in the ICU.

“Most reports of damage to the kidneys have been in people who were hospitalized with COVID-19. Some people who don’t need to be hospitalized may experience damage to their kidneys.”

The results of a 2021 study suggest that people who weren’t hospitalized with COVID-19 are still at an increased risk of adverse kidney outcomes in the future. This suggests that COVID-19 can also impact the kidneys in less serious illness.


The risk of AKI seems to be highest among those with more serious COVID-19 illness. There is evidence that COVID-19 may increase the risk of future kidney disease in people who were not hospitalized with the illness.

A 2021 study looked at the outcome of 143 people who’d been hospitalized with COVID-19 and experienced new-onset kidney disease during their illness.

A study found that 9 percent of people who had a follow-up period did not recover from their disease. The people in the nonrecovery group were older than the people in the recovery group.

Other research has shown that decreased kidney function can be caused by COVID-19.

A 2021 study compared people hospitalized with COVID-associated AKI to those with AKI due to another cause. This was done by assessing eGFR, a measure of the filtering ability of the kidneys, after discharge from the hospital.

The rate of eGFR decrease for people with COVID-associated AKI was greater than for those with AKI due to other causes.

The 2021 study mentioned earlier compared kidney function in veterans who had had COVID-19 and those who had not. The risk of serious kidney events after acute illness was found to increase with the severity of COVID-19.

The risk of serious kidney events in nonhospitalized participants was higher than in people who had not developed COVID-19. This was included.

  • A 15 percent higher risk of a major adverse event.
  • A 30 percent higher risk of AKI.
  • a 215 percent higher risk of end-stage kidney disease

These findings suggest that people who’ve had COVID-19 may need additional follow up after their illness that includes assessments of kidney function. This is particularly true for people who were hospitalized with COVID-19.

Various studies have looked into risk factors for developing AKI or other kidney issues due to COVID-19. Based on the findings of these studies, potential risk factors for kidney issues from COVID-19 may include:

“COVID-19 doesn’t typically have a symptom of the kidneys. It is possible for people with COVID-19 to feel pain in their lungs, which is related to their kidneys.”

“COVID-19 can damage the kidneys, but it doesn’t usually cause pain. Most of the research into the effects of COVID-19 is in hospitalized patients, but it may affect the kidneys of people with less severe illness.”

Some people with chronic kidney disease and other health conditions are at a higher risk of having COVID-related issues. If you have had COVID-19, your doctor may recommend a follow-up test to assess your kidneys function.