Visible vs. Invisible Blood in Urine
Blood in urine (hematuria) comes in two forms: microscopic (invisible to the naked eye), or gross (visible blood in urine). In order to detect microscopic hematuria, only a urinalysis will work. Gross hematuria is plainly visible in urine or during urination due to discolored urine. Both types are a result of a leak of blood cells into the urinary tract.
Hematuria, both gross and microscopic, is often associated with not having symptoms. However, sometimes symptoms can occur.
Possible Symptoms of Blood in Urine
- Abdominal or flank pain
- Frequent and/or painful urination
- Decreased urinary stream
- Frequent urination
Causes of Blood in Urine
The potential causes of hematuria, both microscopic or gross, vary in range – from harmless and non-significant, to potentially serious.
Urinary Tract Infection: Urinary Tract Infections occur when bacteria enters the body through the urethra and begin to multiply in the bladder. Symptoms can include a persistent urge to urinate, pain and burning while urinating, and unusually strong-smelling urine. Some UTIs are associated with blood in urine.
Urinary Tract Cancer: This is the most serious cause of blood in urine. Cancer of the urinary tract may cause gross (visible) bleeding in the urine, whether from cancer in the kidney, ureter, bladder, prostate, or urethra.
Bladder or Kidney Stones: The minerals in concentrated urine sometimes precipitate out, which can form crystals on the walls of the kidneys or bladder. Over time, the crystals may become small, hard stones. The stones are sometimes silent and painless, but if they begin to move and cause blockage, they can cause excruciating pain. At that point, the source of the blood in the urine is clear. Kidney stones are capable of causing pain that is comparable to that of childbirth. Bladder or kidney stones can cause both gross and microscopic bleeding.
Enlarged Prostate: The prostate gland, which is located just below the bladder and surrounds the top part of the urethra, typically begins growing as men approach middle age. When the gland enlarges, it can press down upon the urethra, partially blocking urine flow. Enlarged prostates are more prone to bleeding.
Kidney Infection: A kidney infection (pyelonephritis) can occur when bacteria enters the kidneys from your bloodstream, or when bacteria moves up from the ureters to the kidney (or kidneys). Signs and symptoms of a kidney infection are often similar to bladder infections, although kidney infections are more likely to cause fever and flank pain.
Kidney Disease: Microscopic (invisible) urinary bleeding is a common symptom of glomerulonephritis, which causes an inflammation of the kidney’s filtering system.
Kidney Injury: An external injury or blow to the kidneys from an accident or contact sport can be a potential cause of blood in urine.
Medications: The anti-cancer drug cyclophosphamide (Cytoxan) has been known to cause urinary bleeding. Gross urinary blood sometimes occurs if the patient takes an anticoagulant, such as aspirin or the blood thinner heparin, in conjunction with a condition that causes your bladder to bleed.
Strenuous Exercise: Although it is uncommon, blood in urine may be linked to bladder trauma, dehydration, or the breakdown of red blood cells that occurs during sustained aerobic exercise. Runners are most often affected, although almost any athlete can develop visible urinary bleeding after an intense workout.
Treatment of Blood in Urine
Treatment can vary based on the underlying cause of hematuria. The standard diagnosis process for hematuria usually involves your urologist obtaining an imaging test (ultrasound or CT scan) along with performing a cystoscopy, during which a small fiberoptic camera is inserted into the bladder to ensure that there are no tumors or stones.
If you have seen blood in your urine, or if it has been detected microscopically by your primary care provider, it is urgent for you to see a urologist to determine the underlying cause of your hematuria.