Guide to RBC in Urine

WRITTEN BY

The Levels Team

Updated: 05/22/2025|12 min read

Summary

Red blood cells (RBCs) in urine occur when blood leaks into the urinary tract. While microscopic amounts are typically not cause for concern, persistent or visible blood in urine is often a sign of an underlying condition.

Why It Matters

Red blood cells (RBCs) are blood cells that carry oxygen throughout your body. When RBCs appear in urine, also known as hematuria, it means that they're leaking into the urine at some point along the urinary tract---from the kidneys to the bladder to the urethra. A number of factors can cause this, including intense exercise, urinary tract infections (UTIs), a bladder or kidney stone, or other underlying health issues.

There are two types of hematuria. Gross hematuria is when you can see blood in the urine. Urine may be tinged pink, red, or tea-colored. Microscopic hematuria is not visible to the eye, even though there are red blood cells present.

Elevated RBC readings can result from intense physical activity or menstruation, and are typically not a cause for concern. Also, many causes of RBCs in urine are not serious, like having a UTI. Your healthcare provider will likely order other tests or a retest to understand the cause of the RBC in urine. 

Associated Symptoms 

Red blood cells (RBCs) in urine are laboratory findings rather than medical conditions. However, their presence may be associated with various underlying conditions, each with its own symptoms.

Common symptoms that may indicate conditions associated with RBC in urine:

• Pink, red, or cola-colored urine: Direct visual evidence of gross hematuria, potentially indicating urinary tract bleeding
• Lower back or flank pain: May suggest kidney stones, kidney infection, or other kidney disorders
• Painful or burning urination: May indicate urinary tract infection or inflammation
• Increased urinary frequency or urgency: Can occur with bladder irritation or infection
• Blood clots in urine: May indicate more significant bleeding, potentially from kidney or bladder issues
• Abdominal or pelvic pain: May occur with various conditions, including kidney stones or bladder disorders
• Fever and chills: Can be present with urinary tract infections that have reached the kidneys

It's important to note that many conditions causing RBCs in urine, particularly microscopic hematuria, may produce no noticeable symptoms at all. This is why urinalysis can be valuable for detecting potential issues before symptoms develop. When RBCs are found during routine testing in the absence of symptoms, additional evaluation is often needed to determine their significance.

Clinical Ranges

Lab Reference Range: ≤2 /HPF

Lifestyle Factors That Can Impact It

Activities that may promote RBCs in urine include:

• Intense exercise: Very strenuous exercise, particularly long-distance running or high-impact activities, can cause trauma to or irritate the urinary tract, leading to temporary blood in urine. This is known as exercise-induced hematuria and typically goes away within 24 hours with rest.

Other habits can increase the risk of urinary tract infections, which can lead to RBCs in urine, such as:

• Personal hygiene: Poor hygiene practices can introduce bacteria to the urinary tract. Proper wiping technique (front to back), regular cleaning, and wearing breathable cotton underwear can help prevent bacterial growth.
• Sexual activity: Frequent sexual activity can increase the risk of UTIs, especially in women. Urinating before and after sexual activity can help reduce bacterial transfer.

Other Factors That Can Impact It

Genetic Conditions

• Sickle cell disease: An inherited condition where red blood cells become crescent-shaped and break down easily, which can lead to blood in urine.
• Alport syndrome: A genetic disorder affecting the kidney's filters, causing progressive kidney damage and blood in the urine.
• Polycystic kidney disease: An inherited condition causing fluid-filled cysts to grow in the kidneys, which can rupture and cause bleeding
• Hemophilia: A disorder that impairs blood clotting.

Medical Conditions

• Urinary tract infections (UTIs). UTIs are one of the most common causes of elevated RBCs in urine. The infection causes inflammation of the urinary tract lining, leading to increased red blood cells.  
• Kidney stones. These are mineral deposits that can develop in the kidneys. They can scrape and damage the urinary tract as they move, causing bleeding.
• Glomerulonephritis. This kidney condition involves inflammation of the filtering units (glomeruli), allowing RBCs to leak into urine.
• Advanced bladder, kidney, or prostate cancer. While less common, these conditions can cause persistent hematuria.
• Enlarged prostate. In men, an enlarged prostate puts pressure on the urethra and bladder, potentially leading to inflammation and bleeding.
• Rhabdomyolysis. Occurs when there's severe damage to muscle tissue. 

Medications and Supplements

• Blood thinners (such as aspirin or warfarin)
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Certain antibiotics

Individual Factors

• Age: Older adults have a higher risk of developing  conditions that can cause blood in urine, such as an enlarged prostate or urinary tract cancers
• Gender: Men are more prone to hemophilia and kidney stones, while women are more prone to UTIs
• Pregnancy: The increased pressure on the bladder can cause UTIs
• Menstruation: Can contaminate urine samples with blood
• Body Mass Index: Obesity increases the risk of kidney stones and puts additional stress on the urinary system

Testing Accuracy and Stability

Factors That Can Affect the Accuracy of Your Test 

• Menstrual blood contamination
• Recent sexual activity
• Strenuous exercise 24-72 before testing

How it Relates to Other Markers

Your provider will order other tests to find out the source of the red blood cells in your urine. Some of these tests might include:

• Protein in urine (Proteinuria). Often appears alongside hematuria in conditions affecting kidney function. The presence of both markers can indicate more significant kidney involvement.
• White blood cells (WBCs). Elevated WBCs with hematuria may indicate inflammation from an infection, such as a UTI.
• Nitrites and leukocyte esterase. These markers help confirm or rule out urinary tract infections when RBCs are present in urine.

Follow-up Considerations

If RBC in your urine is high, your provider may recommend these follow-ups. You should always speak to your doctor if you have medical questions or before making medical decisions.

When Re-Testing May be Appropriate

• After initial abnormal results (within 2-4 weeks)
• Following completion of treatment
• Regularly if monitoring a chronic condition

Additional Testing Your Doctor May Consider

• Complete blood count (CBC)
• Comprehensive metabolic panel
• Kidney function tests
• Urine culture
• Imaging studies (CT, ultrasound)
• Cystoscopy (when indicated)

When Additional Care May be Warranted

• Visible blood in urine
• Accompanying symptoms like fever, severe back/flank pain, difficulty urinating, or unexplained weight loss
• Blood in urine persists for more than two weeks 

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