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Blood in the Urine

Blood in the Urine

The presence of blood in your urine, no matter how little, can be a frightening experience. Frequently, it is not life-threatening. For some people, even a mere intense exercise session is enough to cause hematuria (presence of blood in the urine). However such symptoms must not be ignored as they could indicate more serious health conditions that only a health professional should assess.

“Hematuria is a term put together from the Greek words haima (blood) and ouron (urine) to refer to the presence of blood in the urine. The blood may be visible to the naked eye (macrohematuria, gross or frank hematuria) or only under the microscope (microhematuria). In some patient groups it is a frequent finding. The reported prevalence of asymptomatic microhematuria (aMH) ranges between 1.7% and 31.1%; in routine clinical practice, a prevalence of 4% to 5% appears realistic”1

What is blood in the urine?

It refers to the presence of red blood cells in urine (also known as frank or gross hematuria). It’s usually enough to change the color of water in a toilet bowl although it can also be invisible to the naked eye (microscopic hematuria). Hematuria is diagnosed during screening sessions or urinalysis.

“Hematuria is a prominent symptom in diseases of the genitourinary tract, and, moreover, it is often the only symptom of which the patient complains in the early stages. In such cases the first duty of the surgeon is to apply all the means at his disposal for discovering from which portion of that tract the blood is issuing.”2

“Hematuria is common, seen in 2% to 30% of the adult population. Older patients and smokers have higher rates of hematuria. Smokers are also at an increased risk of genitourinary cancer.”3

Hematuria sources

  1. Upper urinary tract: because of problems related to the kidneys.
  2. Lower urinary tract: because of problems associated with the ureters, the bladder and or the urethra.

Symptoms related to urinary tract infections that may indicate Hematuria

“When passing blood in urine is associated with pain, especially abdominal pain, it could be associated with kidney or ureteral stones. The pain could be localized to the back, to the side, to the groin, or the penis in men and the labia in women. If you are passing different-shaped clots in your stream, they could represent bleeding from the urethra or prostate (in men). Clots can be wormlike, and if associated with pain it could represent clots coming from your ureters(tubes from your kidneys to your bladder).”4

  • Weight loss for unknown reasons (mostly in chronic infections).
  • Pain or burning feeling when passing urine.
  • Urinating many times, at times meager amounts.
  • Elevated body temperature, chills, rigor,  abdominal pain, ache in the sides and back.
  • Difficulty in passing urine or urine initiation.
  • Blood clots in urine.
  • Painful sexual relations.
  • Heavy menstrual bleeding (menorrhagia).
  • Urine leaks or occasional dribbling.
  • Waking up many times to urinate at night.

Specific causes of Hematuria related to the urinary tract

“Hematuria can be caused by a variety of conditions including stones, infection, a tumor, or injury involving the kidneys, urinary tract, prostate gland and/or genitals. It could also be caused by a bleeding disorder or by taking certain medications.”5

  • Renal stones.
  • Urinary tract infections.
  • Cystitis (infection or inflammation of the bladder).
  • Inflammatory conditions of the urethra.
  • Inflammatory conditions and infections of the kidneys (glomerulonephritis).
  • Cancerous conditions of the kidneys, the bladder and or the prostate.
  • Trauma to the urinary tract.
  • Surgical or other medical-related procedures of the urinary tract including catheterization and circumcision.
  • Polycystic disease of the kidneys.
  • Prostate hypertrophy.
  • Kidney failure (end-stage and acute).
  • Glomerulonephritis that follows streptococcal infections in children.
  • Medications such as rifampicin, aspirin, warfarin, quinine and phenytoin sodium.
  • Blood disorders that can lead to blood in urine:
  • Blood clotting disorders such as hemophilia.
  • Sickle cell disease.
  • Kidney thrombi.
  • Low platelet count.
  • Leukemia (blood cancer)

“Hematuria can be confused with other urine discoloration caused by something other than blood in the urinary tract, such as foods like beets, bleeding from menstruation, blood from the gastrointestinal system, or medications.”6

“The treatment for hematuria varies and is dependent upon the cause. Your doctor will focus treatment on the condition or disease causing the blood in your urine. If stones are determined to be the cause of hematuria, treatment may require surgery. If your doctor suspects a tumor in the urinary tract or prostate gland based on the imaging, a biopsy may be recommended and possible treatments may include chemotherapy, surgery or radiation therapy.”7

What to do when Hematuria is discovered

“Haematuria may be recognised by the patient; so-called ‘frank’, ‘visible’, or ‘macroscopic’ haematuria. Alternatively, it may be detected only on examination of urine, most commonly as a positive urinalysis test for blood (chemical dipstick), or as more than a set number of red cells per high-power field on microscopy, or in a Coulter counter. Under these circumstances, it is called ‘non-visible’, ‘invisible’, or ‘microscopic’ haematuria. Isolated non-visible haematuria is defined as three or more red blood cells per high-power field in the absence of infection or proteinuria. What is considered ‘normal’ varies greatly as healthy people lose around a million red blood cells in their urine daily, equating to around one cell per high-power field. Chemical dipsticks give a ‘negative’ finding with this level of haematuria.”8

Check with a doctor immediately. Hematuria is usually painless with no other symptoms. A thorough investigation should be performed to determine an early diagnosis and treatment. If a urinary tract infection is already present, avoid bladder irritants such as tea, coffee, cola drinks, and citrus fruit juices.

Confirming the causes of Hematuria

“Hematuria is diagnosed with urinalysis, which is testing of a urine sample. The urine sample is collected in a special container in a health care provider’s office or commercial facility and can be tested in the same location or sent to a lab for analysis. For the test, a nurse or technician places a strip of chemically treated paper, called a dipstick, into the urine. Patches on the dipstick change color when RBCs (red blood cells) are present in urine. When blood is visible in the urine or a dipstick test of the urine indicates the presence of RBCs, a health care provider examines the urine with a microscope to make an initial diagnosis of hematuria. The next step is to diagnose the cause of the hematuria.”9

“Macrohematuria always requires investigation. The hematuria may be visible from a concentration as low as 1 mL blood per liter of urine. The color and the intensity of the color correlate with the amount of blood content: fresh arterial blood (bright red, ranging from pink to ketchup-colored) can be distinguished from venous blood (dark red, Bordeaux red) and from old blood (dark brown or black). Rarely, urine may be colored red or dark owing to myoglobinuria (due to rhabdomyolysis) or hemoglobinuria (due to hemolysis). A diagnosis of hematuria is confirmed by demonstration of red blood cells in the urinary sediment as shown by qualitative and quantitative microscopy. In microhematuria, there is a microscopic increase in red blood cell content above the physiological threshold. The threshold is given as either ≥ or >3 red blood cells per high-power field in microscopic assessment of the urinary sediment in two out of three correctly collected urine samples. Some medical specialty societies regard evidence from one dipstick as adequate, while others require more than just one (e.g., positive results on two out of three dipsticks) for a diagnosis of “significant” microhematuria.”10

A number of tests can help establish the root cause(s):

  • Urine analysis including culture and sensitivity tests.
  • Blood tests.
  • Imaging investigations such as IVP (intravenous pyelogram), X-ray, CT (computerized tomography) and even MRI (magnetic resonance imaging).
  • Cystoscopy.
  • Other research targeting surrounding tissues so as to rule out other underlying health disorders.

“Hematuria is a common clinical finding and represents the most frequent presenting symptom/sign of urothelial carcinoma of the bladder, particularly among persons 40 years and older. Proper evaluation of hematuria is necessary to identify the one person in ten who may have a life-threatening malignancy or other treatable condition. The American Urological Association (AUA) Best Practice Guidelines recommend that all patients 35 years and older, presenting with asymptomatic hematuria (>3 red blood cells per high-power field), for which benign causes have been ruled out, undergo cystoscopy. Additionally, these guidelines recommend evaluation of the renal parenchyma and urothelium, with CT urography (CTU) being the preferred imaging modality.”11

“Many causes of blood in the urine are not necessarily preventable, such as urinary tract infection or cancer, enlargement of the prostate, blood diseases, and kidney diseases. Other causes, like strenuous exercise and the use of certain medications, can be preventable to some extent. Maintaining adequate hydration can be helpful in reducing the chance of developing kidney stones.”12


(1, 10) The Investigation of Hematuria. Bolenz, C., Schröppel, B., Eisenhardt, A., Schmitz- Dräger, B., & Grimm, M. Deutsches Ärzteblatt International. 2018.

(2) Surgery: Some Causes of Hematuria. The Hospital: Biomedical Journal Digitization. 1909.

(3, 6) Blood in the Urine (Hematuria). Matulewicz, R., & Meeks, J. Journal of American Medical Association. 2016.

(4) Hematuria: Blood in the urine. University of Iowa Hospitals & Clinics. University of Iowa Health Care. 2017.

(5, 7) Hematuria or Blood in Urine.  Radiological Society of North America. For Patients. 2018.

(8) Non-visible versus visible haematuria and bladder cancer risk: a study of electronic records in primary care. Price, S., Shephard, E., Stapley, S., Barraclough, K., & Hamilton, W. British Journal of General Practice. 2014.

(9) Hematuria: Blood in the Urine. The National Kidney and Urologic Diseases Information Clearinghouse. 2012.

(11) Variation in the intensity of hematuria evaluation: a target for primary care quality improvement. Friedlander, D., Resnick, M., You, C., Bassett, J., Yarlagadda, V., Penson, D., & Barocas, D. The American Journal of Medicine. 2014.

(12) Blood in the urine reasons. Stöppler, M. eMedicineHealth. 2018.

María Laura Márquez
13 October, 2018

Written by

María Laura Márquez, general doctor graduated from The University of Oriente in 2018, Venezuela. My interests in the world of medicine and science, are focused on surgery and its breakthroughs. Nowadays I practice my more:

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