Winter is a time of viral infections, such as COVID, which "celebrates" its fifth anniversary in 2025 since the pandemic began in 2020.
It may sound surprising to many since COVID is usually considered a bad cold. Nevertheless, reduced renal function can be an outcome of a COVID-driven infection or long COVID. Long COVID is defined as a chronic condition that occurs after SARS-CoV-2 infection and lasts for at least three months. It includes a wide range of symptoms or conditions that may improve, worsen, or persist.
Reduced renal function can lead to:
1. Acute Kidney Injury (AKI)
COVID-19 has been associated with an increased risk of acute kidney injury, especially in severe cases. This can occur due to:
Severe inflammation: The immune response to the virus can cause widespread inflammation, damaging the kidneys.
Low blood oxygen levels: Severe COVID-19 can lead to hypoxia (low oxygen levels), impairing kidney function.
Viral infection of kidney cells: Though still under research, SARS-CoV-2 may directly infect kidney cells, contributing to kidney dysfunction.
Dehydration: Severe symptoms like fever, vomiting, and diarrhea can lead to dehydration, increasing the risk of kidney damage.
2. Chronic Kidney Disease (CKD)
For individuals who already have chronic kidney disease, COVID-19 can worsen kidney function. Infection-related inflammation, combined with the body's inability to cope with stress, can further decline kidney health. Studies show that people with CKD who contract COVID-19 are more likely to experience severe complications.
3. Long-Term Kidney Damage
In some cases, patients recovering from severe COVID-19 may experience long-term kidney damage, even after the acute infection resolves. This could manifest as:
Persistent kidney dysfunction (increased creatinine levels or protein in the urine).
Increased risk of developing chronic kidney disease later on.
Potential long-term damage to blood vessels in the kidneys, affecting their ability to filter waste.
The impact of COVID or long COVID on the kidneys needs to be taken seriously.
The Importance of Kidney Function
The kidneys are essential organs performing several crucial functions. Primarily, they filter waste products and excess substances (like water, salts, and toxins) from the blood to form urine. This helps maintain the body’s balance of fluids, electrolytes, and pH levels. They also help regulate blood pressure, produce hormones for red blood cell production and calcium regulation, and maintain the body’s internal balance (homeostasis).
Supporting kidney health involves a combination of lifestyle habits and regular monitoring. Here are key ways to maintain kidney health:
Stay hydrated.
Eat a balanced diet.
Keep blood pressure and blood sugar levels within normal ranges.
Exercise regularly.
Limit the use of ibuprofen and alcohol.
Get regular check-ups.
What to Do If You Suspect COVID-19 Affected Your Kidneys
If you suspect COVID-19 may have impacted your kidneys, it’s important to take action promptly. COVID-19 can cause kidney problems, even in people who recover from the initial infection. Follow these steps:
1. Watch for Symptoms of Kidney Issues:
Be alert for signs of kidney damage, such as:
Changes in urination (increased or decreased frequency, dark-colored, or foamy urine).
Swelling in the legs, ankles, feet, or around the eyes.
Unexplained fatigue.
Shortness of breath.
Persistent nausea or vomiting.
Back pain near the lower back or flanks.
2. Contact Your Healthcare Provider:
Schedule an appointment: If any symptoms concern you, consult your doctor.
Discuss your COVID-19 history: Let your doctor know about your recent infection, as it may relate to kidney issues.
Get referrals: Your doctor might refer you to a nephrologist for specialized care.
3. Get Kidney Function Tests:
Your doctor may order tests such as:
Serum creatinine: Elevated levels can indicate kidney damage.
Estimated glomerular filtration rate (eGFR): Measures kidney filtering efficiency.
Blood urea nitrogen (BUN): Assesses waste in your blood.
Urinalysis and Albumin-to-Creatinine Ratio (ACR): Detects abnormalities like blood or protein in urine, which could indicate kidney damage.
Electrolyte levels: Checks for imbalances that may signal kidney dysfunction.
4. Monitor Blood Pressure:
High blood pressure can worsen kidney damage, so it’s important to keep it in a healthy range (around 120/80 mmHg). Regularly check it, especially if you had high blood pressure during COVID-19.
5. Hydration and Diet:
Staying hydrated and eating a kidney-friendly diet can aid recovery. Limit salt intake, avoid excessive protein, and focus on a diet rich in fruits and vegetables.
6. Consider Follow-Up for Long COVID:
If you experience lingering symptoms after recovering from COVID-19, ask your doctor about follow-up care and testing for potential kidney issues.
7. Manage Pre-existing Conditions:
Diabetes and hypertension: Properly manage these conditions to prevent further kidney damage.
Medication review: Discuss any changes with your healthcare provider.
8. Follow-Up Imaging (if recommended):
Your doctor may recommend imaging tests like kidney ultrasounds or CT scans to check for structural damage from COVID-19.
9. Long-Term Monitoring:
Even without symptoms, your doctor may recommend regular monitoring of kidney function for several months post-COVID, especially if you had a severe infection.
Key Takeaway:
If you suspect kidney involvement after having COVID-19, seek medical advice early. Kidney issues can develop post-viral infections, and early detection helps prevent complications. Monitoring symptoms, undergoing tests, and following healthcare guidance are key to maintaining kidney health post-COVID.
References:
1. Guyton and Hall Textbook of Medical Physiology (13th Edition) by Arthur C. Guyton and John E. Hall – A comprehensive source for understanding kidney function and physiology.
2. Human Physiology: An Integrated Approach (7th Edition) by Dee Unglaub Silverthorn – Another excellent resource that covers the anatomy and function of the kidneys in detail.
3. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) – Their website offers accessible, scientifically-backed information on kidney health and functions. www.niddk.nih.gov
National Kidney Foundation (NKF): This organization provides in-depth resources on kidney health, prevention, and disease management. www.kidney.org
2. Centers for Disease Control and Prevention (CDC): The CDC has extensive information on chronic kidney disease, its prevention, and tips for maintaining kidney health. www.cdc.gov/kidneydisease
3. American Kidney Fund (AKF): Offers educational content on how to protect your kidneys and maintain overall kidney health. www.kidneyfund.org Assessed and Endorsed by the MedReport Medical Review Board