Hematuria is the term for the presence of blood in the urine. Normally there is only a trace amount of blood in urine although there is a high quantity of the pigment deposits and other components present from broken down blood cells. In hematuria, blood is detected in the urine and this can be microscopic where it is not evident by the naked eye, or macroscopic / gross when it can be clearly seen. Even in gross hematuria, the urine may not be red and bloody but there is an abnormal hue to the urine due to the presence of blood. The urine may look very dark yellow, mustard or brown, orange, pink or even red. However, it is important to note that these abnormal colors of urine are not always due to blood.
Where is the bleeding in hematuria?
The urinary tract is composed of the kidneys at the top, ureters which carry urine away from the kidney, the bladder which stores urine and the urethra which expels the urine into the exterior. Bleeding can occur from any of these sites. Macroscopic hematuria is more common when the disease involves the kidney and/or bladder as these structures are highly vascularized.
Normally the blood is filtered in the renal medulla and cortex of the kidney and salts and water are passed in and out of the tubules. Blood cells usually do not enter the nephron – the basic functional unit of the kidney composed of the glomerulus and tubules. The tubular fluid eventually becomes urine and collects in the renal pelvis of the kidney. It is then passed out into the ureter for storage in the bladder. Each of these structures are surrounded by blood vessels which can be ruptured for any number of reasons and pass out blood cells into the urine. The glomerulus which collects the fluid from the blood can also be damaged and thereby allow blood cells to enter into the nephrons although the blood vessels are intact.
Causes of Hematuria
Hematuria is more common in women. This correlates with the fact that UTIs (urinary tract infections) are more common in females than males. UTIs are the most common cause of acute hematuria and is usually due to a bacterial infection. Another common cause are urinary stones. These stones may form in the kidney (kidney stones) or bladder (bladder stones). As the stones pass through the urinary tract, particularly through the narrow ducts, it injures the walls and causes hematuria.
In women, there is also the possibility that the blood is not stemming from the urinary tract. Instead the urine may be contaminated with blood from the vagina during menses, or due to an infection or other disease affecting the genital tract.
Less common causes of hematuria :
- Kidney infections
- Kidney disease
- Trauma to the kidney
- Cancer of the kidney or bladder
- Blood disorders like sickle cell anemia
- Certain medication
- Strenuous exercise
Although some of these causes are less common or even rare, it should only be excluded after thorough investigation. Some of these conditions are very serious and potentially life threatening.
Treatment of Hematuria
Hematuria is a not a disease on its own. It is a symptom of an underlying disease and is usually accompanied by other urinary problems and symptoms. However, not every case of hematuria is a cause for concern and can sometimes be due to unknown factors where it passes on its own within a very short period of time. The presence of other signs and symptoms as well as the findings of investigative tests will allow your doctor to identify the cause. In order to treat hematuria, the causative condition itself has to be treated and there is no specific medication just for blood in the urine.