Yes, COVID-19 can cause blood in the urine, though it is not a common symptom. Medical reports and studies have documented cases where the SARS-CoV-2 virus leads to hematuria, the medical term for blood in the urine. This typically happens through kidney injury, which can occur during severe infection or as part of the body’s intense inflammatory response to the virus.
How Does COVID-19 Affect the Kidneys?
The kidneys are not spared from COVID-19. The virus can enter kidney cells because those cells have ACE2 receptors, the same entry points the virus uses in the lungs. When the virus attaches to these receptors, it can cause direct damage to the kidney tissue.
Beyond direct infection, the immune system’s response plays a major role. In severe cases, the body releases large amounts of inflammatory proteins called cytokines. This “cytokine storm” can injure the tiny blood vessels inside the kidneys, leading to leakage of blood into the urine.
Blood in the urine from COVID-19 is usually microscopic. That means you cannot see it with the naked eye. It is found during a urine test. Visible blood, where urine appears pink, red, or brown, happens less often but has been reported.
Can Covid 19 Cause Blood In Urine Through Other Mechanisms?
Kidney injury from COVID-19 is not the only path to hematuria. Some patients develop blood clots because the virus triggers abnormal clotting activity. If a clot forms in the kidney’s blood vessels, it can damage tissue and cause blood to appear in the urine.
Dehydration is another factor. Severe illness often reduces fluid intake. Concentrated urine can irritate the urinary tract, and in some cases, this leads to minor bleeding. This is not specific to COVID-19, but it can happen during any serious infection.
Some medications used in hospital settings for severe COVID-19, such as certain antiviral drugs or blood thinners, can also increase bleeding risk. Blood thinners, in particular, do not cause kidney damage, but they can make any existing bleeding more noticeable.
What Does the Research Show?
Studies published in nephrology journals have consistently found that acute kidney injury occurs in a significant percentage of hospitalized COVID-19 patients. Estimates vary widely, with some studies reporting kidney injury in roughly 20% to 40% of intensive care patients. When kidney injury occurs, blood in the urine is one of the possible findings.
Research published in the Kidney International journal described the kidney tissue damage seen in COVID-19 patients. The findings showed injury to the tubules, the parts of the kidney that filter waste, and the presence of red blood cells in the urine samples.
Some research suggests that patients who had blood in their urine during a COVID-19 infection were more likely to have a longer hospital stay. However, the evidence here is not yet strong enough to use hematuria as a reliable predictor of disease severity.
Is Blood in the Urine a Sign of Long COVID?
Persistent kidney issues after COVID-19 have been reported, but the evidence is still emerging. Some patients who recover from severe infection continue to show signs of kidney damage, including protein or blood in the urine, for months afterward.
For most people, however, blood in the urine resolves once the infection clears. If you had blood in your urine during COVID-19 and it disappears, that is generally a good sign. If it persists or recurs after recovery, you should see a doctor.
Long COVID is a real condition, but hematuria is not among its most commonly reported symptoms. The most frequently reported long COVID symptoms are fatigue, brain fog, and shortness of breath. Kidney-related long-term symptoms appear less common but have not been fully ruled out by current research.
When Should You See a Doctor for Blood in the Urine?
Any episode of visible blood in the urine warrants a medical evaluation. This is true whether you have COVID-19 or not. Visible hematuria can signal a urinary tract infection, kidney stones, or other conditions that require treatment.
If you have COVID-19 and notice blood in your urine, contact your healthcare provider. This is especially important if you also have symptoms like swelling in your legs, reduced urine output, or flank pain. These could indicate more serious kidney involvement.
Microscopic hematuria found during a routine test is less urgent but still needs follow-up. Your doctor will likely repeat the test to confirm the finding and may order further tests to rule out other causes.
Blood in the urine is not always serious. But it is never something to ignore, regardless of the cause.
What Other Conditions Cause Blood in the Urine?
COVID-19 is only one possible cause of hematuria. Many everyday conditions can produce the same symptom. It is important to consider these alternatives, especially if your COVID-19 infection was mild or you are unsure whether you had the virus.
- Urinary tract infections — the most common cause, especially in women
- Kidney stones — often accompanied by severe pain
- Enlarged prostate — common in men over 50
- Strenuous exercise — particularly long-distance running
- Certain medications — including blood thinners and some antibiotics
- Kidney disease — including glomerulonephritis
If you have blood in your urine, your doctor will consider all of these possibilities. The evaluation usually starts with a urine test and may include blood tests or imaging. Do not assume COVID-19 is the cause without a proper evaluation.
How Is COVID-Related Hematuria Treated?
There is no specific treatment for blood in the urine caused by COVID-19. The approach is to treat the underlying infection and support kidney function. In most cases, the bleeding stops as the infection resolves.
For hospitalized patients, treatment focuses on maintaining oxygen levels, managing inflammation, and supporting organ function. If kidney injury is severe, dialysis may be necessary. This is reserved for the most serious cases and is not common.
For people recovering at home with mild symptoms, staying well hydrated is sensible. This does not treat the virus, but it helps the kidneys flush waste and reduces the risk of concentrated urine irritating the urinary tract.
Do not take over-the-counter anti-inflammatory drugs like ibuprofen (Advil, Motrin) without checking with your doctor first. Some evidence has raised concerns that these medications may affect kidney function in certain situations, especially during acute illness. Acetaminophen (Tylenol) is generally considered safer for fever and pain during a viral infection, but always confirm with a healthcare provider.
What Should You Expect at the Doctor’s Office?
Your doctor will start by asking about your symptoms and medical history. They will want to know when you noticed the blood, whether it was visible or found on a test, and whether you have other symptoms like pain or fever.
A urine test called a urinalysis is the first step. This test can confirm the presence of blood and also detect protein, which may indicate kidney damage. Your doctor may also order a blood test to check kidney function by measuring creatinine and BUN levels.
Depending on the findings, imaging such as an ultrasound or CT scan may be recommended. These tests look for structural problems like stones or tumors. The need for these tests depends on your age, symptoms, and whether the blood persists.
Most cases of COVID-related hematuria resolve without any specific intervention. The key is to confirm the diagnosis and rule out other causes that may need treatment.
Can You Prevent Kidney Damage From COVID-19?
Prevention starts with avoiding severe infection. Vaccination remains the most effective tool for reducing the risk of severe COVID-19, which is when kidney injury is most likely to occur. Staying up to date on recommended vaccines is a reasonable precaution.
If you do get infected, staying hydrated is important. This is not a treatment, but it supports your kidneys during the illness. Monitor your urine output. If you notice you are urinating much less than usual, that is a warning sign that needs medical attention.
People with pre-existing kidney disease, diabetes, or high blood pressure are at higher risk of kidney complications from COVID-19. If you have these conditions, discuss a sick-day plan with your doctor before you get infected. Knowing when to seek care in advance is more reliable than deciding in the moment.
Frequently Asked Questions
Can COVID-19 cause blood in urine without other symptoms?
Yes, microscopic blood in the urine can occur without any other urinary symptoms. It is often discovered during routine testing and typically resolves as the infection clears.
How long does blood in the urine last after COVID-19?
In most cases, blood in the urine resolves within a few weeks as the infection clears. If it lasts longer than a month, see a doctor for further evaluation.
Is blood in the urine a sign of severe COVID-19?
Not necessarily. Some people with mild infections have had blood in their urine. However, it is more common in hospitalized patients with severe disease.
Can COVID-19 vaccines cause blood in the urine?
There is no established evidence linking COVID-19 vaccines to blood in the urine. If you notice blood after vaccination, it is more likely unrelated and should be evaluated by a doctor.
