Medically reviewed by Susan Kerrigan, MD and Marianne Madsen
Over the past year, scientists have discovered more and more about just how the coronavirus affects the human body. Initially thought to be solely a respiratory disease, COVID-19 now has been found to affect a startling amount of organs such as the heart, the liver, and even the kidneys. What’s more, it’s not known if damage to these organs is temporary or long-lasting.
Let’s focus on the kidneys in particular. Early reports from the start of the pandemic in China and New York, which highlighted patients with severe cases of COVID-19, say that up to one-third of those hospitalized developed “moderate or severe kidney injury.” After all is said and done, that number could be even higher.
Why can COVID cause kidney damage?
Researchers aren’t exactly sure, but they have theories. Here are some of the most likely possibilities.
Blood clots
It’s known that COVID-19 can lead to blood clots in some cases. Scientists think these clots can clog blood vessels in the kidneys and lead to impaired function.
Cytokine storms
A cytokine storm is an abnormal immune response to a disease. Cytokines are immune system proteins that play a role in the body’s ability to fight off infection. But sometimes–and it’s not known just why–a large influx of cytokines is released as a response to an infection, causing severe inflammation throughout the body. This inflammation can cause health problems such as fever, fatigue, or even organ failure–including the kidneys.
Low oxygen levels
Severe cases of COVID-19 can lead to pneumonia, which in turn can decrease oxygen levels. A low oxygen level in the blood can cause the kidneys to malfunction.
Who’s at risk
Not everyone who develops a severe case of the coronavirus goes on to develop acute kidney injury (AKI). But in a study of US veterans, certain possible risk factors were identified. These include the following:
- Being male
- Being obese
- Having hypertension (high blood pressure)
- Being older
- Being African-American
- Having a lower eGFR (measure of kidney function)
Hypertension medication, kidney issues, and COVID-19
Some patients taking drugs to manage their high blood pressure are concerned about their medication possibly leading to kidney damage. These concerns are based on a study released in 2020 that showed a link between reducing doses of blood pressure medication and preventing kidney damage in COVID-19 patients. However, a later study released in January 2021 found that high blood pressure medications did not influence outcomes in hospitalized COVID patients.
Despite conflicting research, experts advise patients not to stop their blood pressure medications, as this can lead to spikes in blood pressure, which, in turn, can damage the kidneys. Instead, they should discuss their concerns with their doctor.
Treatment and prevention
COVID-19-related AKI can strike without warning–some healthy adults without underlying conditions have experienced a sudden loss of kidney function after contracting the coronavirus. However, by eliminating risk factors such as obesity and hypertension–and taking care of your kidneys by eating a proper diet, avoiding alcohol, and exercising daily–you can reduce your chances of developing kidney damage if you’re infected with COVID-19.
Furthermore, continue taking your hypertension medication if you suffer from high blood pressure. Having high blood pressure, even without any other issues, can increase your risk of kidney damage.
Treating AKI is more difficult than preventing it, but it can also be reversible in many cases, especially if detected early enough. So if you’ve suffered a case of the coronavirus and have been diagnosed with kidney injury, make sure to follow up with your doctor to monitor your kidney function. If your kidney damage is severe, dialysis or other treatments may be required.
References
- Kidney disease & COVID-19
- Coronavirus: Kidney Damage Caused by COVID-19
- Reducing or Eliminating Hypertension Medication Can Help Prevent Kidney Injury in COVID-19 Patients
- CDC Long-Term Effects of COVID-19
- Acute kidney injury with COVID-19 shows potential for ‘lifetime’ impact
- Acute Kidney Injury in a National Cohort of Hospitalized US Veterans with COVID-19
