Blood in the urine, also known as hematuria, can occur in one of two forms. Microscopic hematuria is when blood is detectable only under a microscope. This form is typically detected when men have had a urinalysis as part of an examination either for urinary symptoms or some other health complaint. Gross hematuria is when the presence of blood in the urine is obvious and the urine looks red, pink, or brownish.
What causes blood in the urine of men?
In either case, blood in the urine should not be ignored, as it may be a sign of something serious, although often it is not. For many men, blood in the urine is not accompanied by other symptoms. Here are some of the main causes of blood in the urine.
- Enlarged prostate or prostatitis. Benign prostatic hyperplasia (BPH) may cause microscopic or gross blood in the urine, as may inflammation of the prostate (prostatitis). Both of these prostate conditions are typically accompanied by urinary symptoms such as urinary urgency, urinary frequency, and dribbling, among others.
- Kidney infections. Also known as pyelonephritis, these infections occur when bacteria infiltrate the kidneys from the bloodstream or travel from the ureters to the kidneys. You may experience some flank pain and fever along with the blood.
- Kidney or bladder stones. Both of these stones may cause minute or gross bleeding. Although kidney or bladder stones are often painless, kidneys stones in particular can be especially painful.
- Kidney disease. Microscopic bleeding is often seen with glomerulonephritis, or acute inflammation of the kidneys. It is so named because the small capillaries that filter blood in the kidneys (glomeruli) leak blood.
- Bladder, kidney, or prostate cancer. Each of these cancers can be associated with blood in the urine in the more advanced stages.
- Kidney injury. Trauma to the kidneys related to an accident or sports can cause blood in the urine.
- Inherited conditions. Both microscopic and gross blood in the urine is associated with sickle cell anemia, which is a detect of hemoglobin in red blood cells. Alport syndrome is another disorder that may cause blood in the urine.
- Use of medications. Some over-the-counter and prescription drugs may cause urinary bleeding. Cyclophosphamide (an anti-cancer drug) and penicillin may result in blood in the urine, as may heparin and aspirin.
- Vigorous exercise. Infrequently, vigorous exercise (including strenuous sexual activity) may cause gross hematuria. Runners are the most affected by this type of bleeding, which may be associated with the breakdown of red blood cells that occurs during endurance activity.
How is blood in the urine diagnosed?
Your doctor will likely conduct a physical exam and urinalysis (urine test), which can check for urinary tract infection or the presence of substances involved in the formation of stones. If necessary, your doctor may also order a computerized tomography (CT) scan, magnetic resonance imaging (MRI), or ultrasound to image your bladder and kidneys. A cystoscopy, which involves threading a narrow tube into your bladder to examine it closely, also may be performed.
The cause of blood in the urine is not always apparent or discovered on initial examination. If you are at risk for bladder cancer, your doctor may order additional tests.
How is blood in the urine treated?
If an underlying cause for blood in the urine is detected, treatment of that condition is initiated, such as antibiotics for an infection or therapy for an enlarged prostate. If the cause is not serious, no treatment may be necessary.
References
Nielsen M, Qaseem A, High Value Care Task Force of the American College of Physicians. Hematuria as a Marker of Occult Urinary Tract Cancer: Advice for High-Value Care From the American College of Physicians. Ann Intern Med. 2016 Jan 26. [Medline].
Phillips D. Clinical Guideline on Hematuria Released by ACP. Medscape Medical News. January 28, 2016; Accessed: February 8, 2016.
Tu WH, Shortliffe LD. Evaluation of asymptomatic, atraumatic hematuria in children and adults. Nat Rev Urol. 2010 Apr. 7(4):189-94. [Medline].
Higashihara E, Nishiyama T, Horie S, et al. Hematuria: definition and screening test methods. Int J Urol. 2008 Apr. 15(4):281-4. [Medline].
Quigley R. Evaluation of hematuria and proteinuria: how should a pediatrician proceed?. Curr Opin Pediatr. 2008 Apr. 20(2):140-4. [Medline].
Kashtan CE. Familial hematuria. Pediatr Nephrol. 2009 Oct. 24(10):1951-8. [Medline].
Diven SC, Travis LB. A practical primary care approach to hematuria in children. Pediatr Nephrol. 2000 Jan. 14(1):65-72. [Medline].
Dodge WF, West EF, Smith EH, Bruce Harvey 3rd. Proteinuria and hematuria in schoolchildren: epidemiology and early natural history. J Pediatr. 1976 Feb. 88(2):327-47. [Medline].
Friedlander DF, Resnick MJ, You C, Bassett J, Yarlagadda V, Penson DF, et al. Variation in the intensity of hematuria evaluation: a target for primary care quality improvement. Am J Med. 2014 Jul. 127 (7):633-640.e11. [Medline].
