A report indicating a “non-hemolyzed trace of blood in urine” is a common finding from a routine urinalysis. This article clarifies what this specific result means within the context of a standard lab test. It helps distinguish between common, temporary findings and those that require further medical attention. This information is educational and should not replace the personalized advice of a healthcare provider.
Decoding the Urinalysis Result
This result is composed of three distinct components: “trace,” “blood,” and “non-hemolyzed.” The finding of “blood” in the urine is known medically as hematuria. Trace findings are typically detected chemically using a dipstick, which measures the peroxidase activity of hemoglobin.
The term “trace” signifies a very small amount of blood. This amount is often so minimal that it may not meet the formal definition of clinical microscopic hematuria. A true diagnosis of microscopic hematuria requires finding three or more red blood cells (RBCs) per high-power field (HPF) upon microscopic examination of the urine sediment. A trace dipstick result necessitates a subsequent microscopic review to confirm if the finding is clinically significant.
The term “non-hemolyzed” means the red blood cells detected remained intact, or whole, when the test was performed. This contrasts with a “hemolyzed” result, where the cells have burst and released their hemoglobin into the urine. A non-hemolyzed finding suggests the blood originated lower in the urinary tract or that the urine’s concentration did not cause the cells to break down. The presence of intact red blood cells points toward true hematuria rather than a chemical artifact.
Common and Temporary Reasons for Trace Findings
A trace amount of non-hemolyzed blood in a single urine sample is often a temporary finding that resolves on its own. These transient causes are often benign and situational, linked to a recent activity or event. Vigorous exercise, particularly long-distance running, can temporarily cause red blood cells to appear in the urine.
Dehydration can concentrate the urine, making small amounts of blood more detectable, or it can cause mild irritation to the urinary tract lining. Recent sexual activity or mild trauma may also lead to temporary irritation and bleeding. Contamination from the menstrual cycle is a common reason for a positive blood result in female patients.
Certain medications or foods, such as beets or rhubarb, can interfere with the dipstick test, leading to a false positive or a temporary trace finding. A healthcare provider may recommend repeating the urinalysis after a brief period to see if the finding has disappeared. If the trace amount does not persist, it is generally not a cause for concern.
Underlying Conditions Requiring Further Investigation
If non-hemolyzed blood persists on repeat testing, it requires a thorough investigation to identify an underlying source. A common non-transient cause is a Urinary Tract Infection (UTI), which causes inflammation and irritation leading to bleeding. This is typically accompanied by symptoms like painful or frequent urination, and the urinalysis often shows white blood cells and bacteria.
The presence of kidney or bladder stones can also cause non-hemolyzed blood, as the hard deposits scrape against the lining of the urinary tract. Even small stones can cause irritation that leads to persistent bleeding. Less common but more serious causes include kidney issues, such as glomerular disease, which is inflammation of the kidney’s filtering units.
In these cases, the trace blood is often accompanied by other findings, such as protein in the urine, which points toward a kidney-related issue. For individuals with risk factors, like a history of smoking or being over the age of 40, persistent hematuria necessitates evaluation to rule out structural issues, including masses or cancers. The follow-up protocol often includes a physical examination, repeat urinalysis, and potentially imaging studies like ultrasound or CT scans, or a cystoscopy.