Blood in Urine (Hematuria): Causes, Symptoms & When to Seek Care

What Are the Symptoms of Blood in Urine?

The main symptom of hematuria is urine that appears pink, red, or brown due to blood. The amount of blood determines the color intensity. Gross (visible) hematuria means you can see the color change, while microscopic hematuria is only detected through laboratory testing. Other symptoms depend on the underlying cause and may include pain, frequent urination, or fever.

Normal urine is typically yellow, ranging from pale to dark yellow depending on your hydration level and what you have eaten. When blood enters the urinary tract, it can change the urine's appearance significantly. Understanding these changes helps you recognize when something may be wrong and whether you need medical attention.

The color of bloody urine can vary considerably based on how much blood is present and where in the urinary system the bleeding originates. Fresh blood from the lower urinary tract (bladder or urethra) tends to appear bright red, while blood that has traveled from the kidneys may appear darker or brownish because it has had time to oxidize. Some people describe their urine as looking like cola or tea when blood is present in larger amounts.

It is important to understand that even a small amount of blood can dramatically change the appearance of urine. Just one milliliter of blood in a liter of urine can produce a visible pink or red color. This means that what appears to be a large amount of blood may actually represent only a small amount of bleeding, though all cases should still be evaluated.

Visible blood in urine (Gross Hematuria)

When blood is visible to the naked eye, this is called gross hematuria or macroscopic hematuria. The urine may appear pink, red, or brownish-red depending on the amount of blood present. In some cases, you may also notice blood clots in the urine, which can range from small specks to larger clots. Blood clots can sometimes cause discomfort or difficulty urinating if they partially block the flow of urine.

Gross hematuria is often alarming to patients, but it does not necessarily indicate a more serious condition than microscopic hematuria. However, visible blood in urine always warrants medical evaluation, particularly in adults over 50 years of age or those with risk factors for urological malignancies such as a history of smoking.

Microscopic hematuria

Microscopic hematuria refers to blood that cannot be seen with the naked eye but is detected during laboratory analysis of a urine sample. This type of hematuria is often discovered incidentally during routine health screenings, pre-employment physicals, or when testing for other conditions. Despite being invisible, microscopic hematuria can indicate the same underlying conditions as visible blood and requires appropriate follow-up evaluation.

Studies show that microscopic hematuria affects between 2% and 31% of the general population, with the wide range reflecting different testing methods and populations studied. The clinical significance varies, and many cases resolve spontaneously, but persistent microscopic hematuria requires investigation to rule out serious causes.

Associated symptoms to watch for

Blood in urine may occur alone or alongside other symptoms that can help identify the underlying cause. Pain during urination (dysuria) often accompanies urinary tract infections. Frequent urination or urgency suggests bladder involvement. Flank pain or lower back pain may indicate kidney involvement, such as kidney stones or kidney infection. Fever suggests an infectious cause that may require prompt antibiotic treatment.

What Causes Blood in Urine?

Blood in urine can be caused by urinary tract infections (most common), kidney stones, kidney disease, bladder or kidney cancer, trauma, vigorous exercise, certain medications, and inherited conditions like polycystic kidney disease. In some cases, foods like beets can turn urine red without actual blood being present.

The urinary system includes the kidneys, ureters, bladder, and urethra. Blood can enter the urine at any point along this pathway, and the location of bleeding often provides clues to the underlying cause. Understanding the various causes helps explain why thorough evaluation is important even when symptoms seem minor.

The causes of hematuria range from benign and temporary conditions to serious diseases requiring immediate treatment. In younger patients, urinary tract infections and kidney stones are the most common causes. In older adults, particularly those over 50 and especially men, the possibility of bladder or prostate cancer must be considered, making comprehensive evaluation essential.

Urinary tract infections (UTI)

Urinary tract infections represent the most common cause of blood in urine, particularly in women. When bacteria enter the urinary tract through the urethra and multiply in the bladder, they cause inflammation of the bladder lining (cystitis). This inflammation damages small blood vessels in the bladder wall, allowing blood to leak into the urine. UTIs typically also cause burning with urination, frequent urination, urgency, and sometimes cloudy or foul-smelling urine.

Certain viruses can also cause infections in the urethra or bladder, leading to hematuria. Viral infections often cause significant visible blood in the urine but are usually not serious and resolve within one to three days. These infections may be accompanied by cold symptoms or eye redness, particularly in children.

Kidney stones

Kidney stones develop when minerals in concentrated urine crystallize and form solid deposits. These stones can cause bleeding as they move through the urinary tract, scraping against the delicate lining of the ureters or bladder. Kidney stones often cause severe, colicky pain that radiates from the back to the groin, along with nausea and vomiting. However, some stones cause hematuria without significant pain, particularly if they remain in the kidney or pass easily.

The minerals that form kidney stones can also exist as small crystite of crystal deposits or "sand" in the urinary system, even when large stones have not formed. These smaller deposits can irritate the urinary tract lining and cause microscopic hematuria without the severe pain typically associated with larger kidney stones.

Kidney inflammation (Glomerulonephritis)

Glomerulonephritis refers to inflammation of the kidneys' filtering units (glomeruli). This condition can result from infections, autoimmune diseases, or other systemic illnesses. When the glomeruli become inflamed, they may leak blood and protein into the urine. The blood in urine from glomerulonephritis often appears brown or tea-colored rather than bright red because the blood cells are damaged as they pass through the inflamed kidney tissue.

In children, glomerulonephritis sometimes develops following a streptococcal throat infection (post-streptococcal glomerulonephritis). This typically occurs one to three weeks after the throat infection and usually resolves within a few weeks without treatment. However, some forms of glomerulonephritis require treatment with corticosteroids or other immunosuppressive medications to prevent kidney damage.

Bladder and kidney cancer

While cancer is not the most common cause of blood in urine, it is among the most serious. Bladder cancer and kidney cancer can both cause hematuria, often without pain in the early stages. This painless hematuria is a hallmark presentation that warrants thorough investigation, especially in adults over 50, current or former smokers, and those with occupational exposure to certain chemicals.

Early detection of urological cancers significantly improves outcomes, which is why international guidelines recommend comprehensive evaluation for all adults with gross hematuria and for those with persistent microscopic hematuria, particularly when risk factors are present. The evaluation typically includes imaging studies and cystoscopy to directly visualize the bladder lining.

Benign prostatic hyperplasia (in men)

In men, an enlarged prostate gland (benign prostatic hyperplasia or BPH) can cause blood in the urine. As the prostate enlarges, it can compress the urethra and affect blood vessels near the prostate, leading to bleeding. BPH becomes increasingly common with age and is found in the majority of men over 70 years of age. Symptoms often include difficulty starting urination, weak stream, frequent nighttime urination, and incomplete bladder emptying.

Medications and foods

Certain medications can cause blood in urine or make the urine appear red without actual bleeding. Blood thinners (anticoagulants) like warfarin and newer oral anticoagulants can increase the risk of bleeding throughout the body, including into the urinary tract. However, hematuria while taking blood thinners still requires evaluation to rule out underlying pathology that the medication may have unmasked.

Some foods and medications can turn urine red or pink without actual blood present, a condition called pseudohematuria. Beets, blackberries, blueberries, and rhubarb contain pigments that can color the urine. Medications like rifampin (an antibiotic) and phenazopyridine (a urinary pain reliever) can also cause orange or red urine. A simple urine test can distinguish true hematuria from these harmless color changes.

Physical trauma and exercise

Blood in urine can occur after trauma to the kidneys or bladder, such as from a fall, car accident, or sports injury. Any visible blood in urine following trauma warrants emergency evaluation to assess for kidney or bladder injury. Even seemingly minor trauma can cause significant internal damage that may not be immediately apparent.

Intense physical exercise can sometimes cause temporary hematuria, particularly after activities like running, cycling, or contact sports. This "exercise-induced hematuria" or "runner's hematuria" typically resolves within 24-72 hours of rest. While usually benign, recurrent exercise-induced hematuria should be evaluated to rule out other causes.

When Should You See a Doctor for Blood in Urine?

See a healthcare provider if you notice blood in your urine without an obvious explanation. Seek immediate care if blood in urine is accompanied by fever, severe back or abdominal pain, vomiting, or if it occurs after an accident or injury. People over 50 should be evaluated promptly, even for painless hematuria, to rule out cancer.

Any unexplained blood in urine warrants medical evaluation. While many causes are benign and easily treatable, some require prompt diagnosis and treatment to prevent complications or identify serious conditions early. The urgency of seeking care depends on your age, associated symptoms, and medical history.

In some regions, people over 50 with blood in urine can be referred directly to urology specialists for evaluation. This expedited pathway recognizes the increased risk of urological malignancies in older adults and aims to ensure timely diagnosis.

Seek immediate medical care if:

• You have blood in urine with fever
• You experience severe abdominal or back pain
• You are vomiting along with urinary symptoms
• You feel generally unwell or have other concerning symptoms
• You are unable to urinate despite feeling the urge

Schedule a medical appointment if:

You notice blood in your urine without the urgent symptoms listed above. This is particularly important if you are over 50 years of age, have ever smoked, have a family history of kidney disease or urological cancer, or have previously had blood in your urine. Do not delay evaluation simply because the blood appears to resolve on its own, as intermittent bleeding is common with both benign and serious conditions.

If you take blood-thinning medications (anticoagulants or antiplatelet drugs), you should still be evaluated for blood in urine. While these medications increase bleeding risk, they can also unmask underlying conditions that cause bleeding. Your healthcare provider needs to investigate the source of the blood.

How Is Blood in Urine Diagnosed?

Diagnosis begins with a medical history and physical examination, followed by urinalysis to confirm blood and check for infection. Additional tests may include urine culture, blood tests, ultrasound, CT scan, and cystoscopy depending on your age, symptoms, and risk factors. The goal is to identify the source and cause of bleeding.

When you see a healthcare provider for blood in urine, they will first ask about your symptoms, medical history, medications, and any family history of kidney disease. A physical examination typically includes checking for tenderness in the kidney area and, in men, a prostate examination. For children, a parent or guardian should be present during the examination.

The diagnostic workup is tailored to each patient based on their risk factors, symptoms, and clinical presentation. Younger patients with symptoms clearly suggesting a urinary tract infection may need only basic testing, while older patients or those with risk factors require more comprehensive evaluation.

Urine tests

A urinalysis is the first and most important test for evaluating blood in urine. This test can confirm the presence of blood, detect signs of infection (bacteria, white blood cells), identify protein in the urine (suggesting kidney disease), and reveal other abnormalities. A urine culture may be ordered if infection is suspected, as this identifies the specific bacteria causing the infection and which antibiotics will be effective.

The urine sample should ideally be a "midstream" or "clean-catch" specimen to avoid contamination. This involves starting to urinate into the toilet, then collecting the middle portion of the stream in a sterile container. Proper collection technique is especially important for women to avoid contamination with vaginal secretions or menstrual blood.

Blood tests

Blood tests help assess kidney function and identify systemic conditions that might cause hematuria. Common tests include creatinine (to measure kidney function), complete blood count (to check for anemia or signs of infection), and sometimes tests for autoimmune conditions if glomerulonephritis is suspected.

Imaging studies

Ultrasound is often the first imaging test used because it is non-invasive, does not use radiation, and provides good visualization of the kidneys and bladder. It can detect kidney stones, tumors, cysts, and structural abnormalities. Ultrasound is particularly useful for evaluating children and pregnant women.

CT (computed tomography) scanning provides more detailed images and is particularly useful for detecting kidney stones, tumors, and kidney injuries after trauma. CT urography involves injection of contrast dye to better visualize the entire urinary tract. This test is often recommended for adults with unexplained hematuria, especially those over 50.

Cystoscopy

Cystoscopy involves inserting a thin, flexible camera through the urethra to directly examine the inside of the bladder. This procedure is typically performed with local anesthesia and allows the urologist to see the bladder lining and identify tumors, inflammation, stones, or other abnormalities. Cystoscopy is recommended for most adults with gross hematuria and those with persistent microscopic hematuria, particularly if they are over 35-40 years of age or have risk factors for bladder cancer.

Kidney biopsy

If glomerulonephritis is suspected based on other tests showing protein in the urine or reduced kidney function, a kidney biopsy may be necessary. This procedure involves using a specialized needle to obtain a small tissue sample from the kidney, which is then examined under a microscope to determine the type and severity of kidney inflammation. The procedure is performed under local anesthesia with imaging guidance.

How Is Blood in Urine Treated?

Treatment depends entirely on the underlying cause. Urinary tract infections are treated with antibiotics. Kidney stones may pass naturally or require procedures like shock wave therapy. Kidney inflammation may need corticosteroids. Cancer requires specialized treatment. Sometimes no treatment is needed if the cause is benign and self-limiting.

Because hematuria is a symptom rather than a disease, treatment focuses on addressing the underlying cause. In some cases, once the cause is identified and determined to be benign, no specific treatment is required and the blood in urine resolves on its own. In other cases, prompt treatment is essential to prevent complications or progression of disease.

Treatment for urinary tract infections

Bacterial urinary tract infections are treated with antibiotics, typically for 3-7 days depending on the type and location of infection. The choice of antibiotic depends on local resistance patterns and culture results if available. Most people experience improvement within 24-48 hours of starting treatment, and the blood in urine typically resolves once the infection clears. It is important to complete the full course of antibiotics as prescribed, even if symptoms improve quickly.

Treatment for kidney stones

Small kidney stones often pass naturally with increased fluid intake and pain management. Larger stones may require intervention. Extracorporeal shock wave lithotripsy (ESWL) uses focused sound waves to break stones into smaller pieces that can pass more easily. For larger or more complex stones, ureteroscopy or percutaneous nephrolithotomy may be necessary. A urologist will determine the most appropriate treatment based on stone size, location, and composition.

Treatment for kidney inflammation

Treatment for glomerulonephritis depends on the type and cause. Post-streptococcal glomerulonephritis in children often resolves without specific treatment within a few weeks, though monitoring is important. Other forms of glomerulonephritis may require corticosteroids or other immunosuppressive medications to reduce inflammation and prevent kidney damage. Treatment decisions are based on kidney biopsy findings and the severity of kidney involvement.

Hospital treatment

Some conditions causing blood in urine require hospital admission. Severe kidney infections (pyelonephritis) may need intravenous antibiotics. Significant bleeding with clot formation may require bladder irrigation. Trauma to the urinary system may need surgical intervention. Children requiring hospital care can usually have a parent or family member stay with them.

When no cause is found

Sometimes, despite thorough evaluation, no specific cause for blood in urine is identified. This is called idiopathic hematuria. In these cases, particularly with microscopic hematuria, the healthcare provider typically recommends periodic monitoring with repeat urine tests over several years to ensure no concerning condition develops.

Frequently Asked Questions