Healthy Living

Blood in Urine: What is a Urine Test?

Blood in Urine: What is a Urine Test?

Key Takeaways

  • A urinalysis is a laboratory-based assessment of the components of urine.  
  • Because various factors may lead to blood in urine, urinalysis helps in locating and pinpointing the problem to the kidneys or other problem areas in the urogenital system.

When you pee and see a stream of rusty red urine, the sight fills you with a sense of dread. You suspect that the discoloration is due to the presence of blood. A pungent odor may fuel the anxiety. The only way to confirm suspicions is through a urinalysis recommended by a primary caregiver.  

A urinalysis is a laboratory-based assessment of the components of urine.  The analysis usually occurs in three distinct stages. It involves the physical examination of color and odor, the chemical assessment of compounds and substances in urine, and the microscopic assessment of waste components.  

Blood in urine is not a problem in itself. Bloody urine is the symptom of a disease or disorder affecting the excretory or reproductive system. The problem within the urogenital system may itself be a reflection of disease brewing elsewhere.

A urinalysis happens to be the gateway test to confirm or disprove the presence of blood. Because multiple factors may lead to blood in urine, a urinalysis helps in locating and pinpointing the problem to be in the kidneys or other problem areas in the urogenital system.

An outline of urine testing for hematuria

The sample

The urine sample, unless it is refrigerated, has to be examined within two hours of collection to maintain accuracy and reliability of the results. Samples of the initial or ending pee should normally be avoided; the urine collection has to be done midstream.

Urine color

Coloration by itself can be misleading because certain food items and medication are known to cause discoloration in urine. Beets and blackberries, for example, can impart a reddish tint to urine. A pain reliever like Pyridium imparts an orange hue to urine. Carrots and Vitamin C supplements can turn urine yellow.  A laxative like cascara can make urine brownish black.

Urine odor

Other than the usual urinoid odor, urine may emit a stronger pungent smell if there is a background of urinary infection and inflammation. The presence of blood combining with pus can create a foul smell.

The Urine Dipstick Test

This involves dipping a long thin strip of multiple test patches in urine. The color change in the test patches helps measure the level of blood, protein, glucose, and other components. The test is useful in detecting faint traces of blood in urine and has a sensitivity exceeding 91%. If blood is present, the test strip patches will alter coloration in proportion to the number of red blood cells present. Women may get a false blood positive reading when menstrual blood mixes with urine. Readings may also register higher values when the urine is concentrated and lower in volume (when the body becomes dehydrated).  

The accepted medical definition of hematuria is the detection of at least three red blood cells within a standardized microscopic examination field in a urine sample that has been centrifuged.

The Urine Culture

The presence of white blood cells, cysts, and pus would indicate that the urinary system is under microbial attack. Examination of a culture of the urine sample allows the doctor to locate and identify the specific pathogen that is causing the infection. The presence of crystals would indicate that a stone may be forming somewhere in the urinary system affecting the kidneys, the ureter or the bladder.

Summary of Urinalysis

The external physical evaluation of the urine sample and its microscopic assessment permit multiple findings. They make it possible for the urologist to confirm the nature of the urological or genital causes leading to blood in urine. If the patient is suffering serious distress, further tests such as complete haemogram, X-rays, abdominal ultrasound, and CT scan may be suggested to validate the urinalysis findings.