Urine tests are a routine part of health assessments. One abbreviation commonly seen on these reports is “OCC,” which pertains to the presence of blood in the urine. This article explains the meaning and significance of “OCC” in a urine test, focusing on its role in detecting microscopic blood and the implications of such findings.
Understanding Occult Blood in Urine
“OCC” in a urine test stands for “occult blood,” which refers to blood not visible to the naked eye. This condition is also known as microscopic hematuria. Unlike gross hematuria, where urine appears visibly red, occult blood is present in small quantities, detectable only through specialized laboratory tests.
Detection involves chemical analysis using reagent strips, also known as urine dipstick tests. These strips react with hemoglobin, a protein in red blood cells, indicating blood presence even if red blood cells are not directly observed. If a dipstick test is positive, a microscopic examination of the urine sample confirms and quantifies red blood cells. Significant microscopic hematuria is defined as three or more red blood cells per high-power field (RBC/hpf).
Common Causes of Occult Blood Detection
Occult blood in urine can stem from various reasons, from less concerning issues to more serious conditions. Urinary tract infections (UTIs) are a frequent cause, as bacteria can lead to inflammation and microscopic bleeding. UTIs often present with symptoms like frequent urination or pain during urination. Kidney stones, mineral crystals forming in the kidneys or bladder, can irritate the urinary tract lining as they pass, causing bleeding.
In men, an enlarged prostate, or benign prostatic hyperplasia (BPH), is a common cause, especially in middle-aged and older individuals. The enlarged prostate can compress the urethra, obstructing urine flow and leading to bleeding. Certain kidney conditions, such as glomerulonephritis, where kidney filters become inflamed, can also result in occult blood.
While less common, occult blood can be an early sign of more serious issues, including cancers of the kidney, bladder, or prostate. These cancers might not present with other noticeable symptoms in early stages, emphasizing the importance of investigating occult blood findings. Trauma or injury to the urinary tract or kidneys can also cause microscopic bleeding.
Interpreting Results and Next Steps
A positive result for occult blood indicates red blood cells and necessitates further evaluation to determine the underlying cause. Conversely, a negative result suggests a healthy urinary tract, and no additional testing is required unless other symptoms are present. When occult blood is detected, healthcare providers consider the patient’s medical history, current symptoms, and other test results for a comprehensive understanding.
Initial steps following a positive finding include repeat testing to confirm the result, as transient factors can influence initial readings. If confirmed, additional diagnostic tests may be recommended. These can include urine cultures to check for infections, imaging studies like ultrasound or CT scans to visualize the kidneys and bladder, or a cystoscopy, which involves inserting a small camera into the bladder to examine its lining. Seeking medical advice is important to interpret results accurately and determine appropriate next steps for diagnosis and management.
Factors That Can Influence Results
Several factors can temporarily influence urine test results, leading to the detection of occult blood without indicating a serious medical condition. Strenuous physical activity, such as intense exercise or long-distance running, can cause temporary microscopic hematuria. This exercise-induced hematuria resolves on its own.
For women, menstruation is a common factor that can lead to a positive occult blood result due to contamination of the urine sample with menstrual blood. Menstrual blood contains red blood cells, protein, and hemoglobin, which can mimic the presence of blood from the urinary tract. Healthcare providers often advise collecting urine samples outside of the menstrual period or taking precautions like using a tampon to minimize contamination. Certain medications, including blood thinners (anticoagulants and antiplatelets) and some pain relievers (NSAIDs), can also increase the risk of microscopic bleeding in the urine. Additionally, some dietary factors, such as consuming large amounts of beets, can cause urine discoloration that might be mistaken for blood, although this does not result in a positive occult blood test for red blood cells themselves.