The presence of blood or red blood cells in urine is medically referred to as hematuria. In healthy people, about 2.5 million inefficient, old, and dead red blood cells are eliminated from the body along with urine on a daily basis. However, when healthy RBCs are found it blood, then it can be indicative of some underlying problem.
There are two types of hematuria, i.e., gross hematuria where blood in urine can be easily seen with the naked eye, and microscopic hematuria wherein RBCs in urine are detected by examining a urine sample under a microscope. By definition, microscopic hematuria or microscopic blood in urine refers to over 3 RBCs in a centrifuged urine sample per high-power microscopic field. If microscopic blood in urine is found to be higher than normal range then doctors may perform other tests to find the causative disorder.
Doctors may perform urine tests at regular intervals to verify if microscopic blood in urine is a regular or an intermittent issue. The latter is not a cause for worry, but regular episodes need to be diagnosed for underlying causes and treated accordingly.
Symptoms accompanying microscopic blood in urine
Microscopic blood in urine can occur due to harmless causes or due to severe underlying diseases. Most of the symptoms that patients experience along with microscopic hematuria are associated with the pre-existent ailments. Some of these signs and symptoms are listed below:
- Burning sensations when urinating
- Painful urination
- Increased desire to pass urine frequently
- Pain in the flanks
- Appetite loss
- Weight loss
- Abdominal pain or discomfort
- Fatigue or elevated tiredness
- Fever, sometimes with chills
- Swollen hands, ankles, feet, and face
- Nausea, vomiting
- Putrid smelling urine
Microscopic blood in urine may occur due to the following causes:
- Urinary tract infections/UTIs: A UTI refers to infection of the urinary system by bacteria or other germs. These pathogens can enter the urinary tract from the bloodstream or directly via the urethra when passing urine. The infection can then spread to other renal glands like the kidneys, bladder, etc. Severe infection can damage the urinary system tissues as well as the tiny blood vessels, leading to leakage of blood. Such blood is eventually found as microscopic blood in urine.
- Kidney diseases: Different kinds of kidney infections and diseases can damage the tissues of the organ and cause bleeding and kidney dysfunction. Other chronic conditions like hypertension and diabetes can also indirectly affect and hamper kidney function. An improperly functioning kidney may not be able to filter out RBCs, which then get removed as microscopic blood in urine.
- Bladder and Kidney stones: Urine has many minerals like oxalates, uric acid, calcium, etc. These compounds occur in excessive levels in concentrated urine and over time crystallize and turn into stones. Bladder and kidney stones can then pass through the urinary tract, damage the tissues, and cause bleeding which is then detected as microscopic blood in urine.
- Sickle cell anemia: It is a genetic disease marked by abnormal red blood cells that are shaped like sickles. Hematuria is one of the main symptoms of this disease. The sickle-shaped RBCs cannot carry sufficient oxygen and hence get removed along with urine as inefficient cells, thereby causing microscopic blood in urine.
- Enlarged prostate: Some men tend to suffer from enlargement of the prostate gland, the reasons for which are unknown. However, an increased age of over 50 years can increase the risk to prostate enlargement. The force exerted by the larger prostate on the surrounding organs and tissues can cause damage and bleeding in the urinary system, thereby resulting in microscopic blood in urine.
- Injuries or trauma: A motor accident or other types of trauma that directly impacts the abdominal area and causes damage to the renal organs like the kidneys, bladder, etc., can result in minor internal bleeding. In such cases, patients are most likely to suffer from microscopic blood in urine.
- Cancer: Development of tumors and cysts, due to malignancies like prostate cancer, kidney cancer, and bladder cancer, etc., can also cause put pressure on the surrounding tissues and damage them. The resultant bleeding may then be identified as microscopic blood in urine.
- Intense workouts: Strenuous workouts can sometimes result in hematuria, albeit for a short term. The exact cause of this is not known. But microscopic blood in urine has been detected in urine sample of runners, dehydrated people, and those who do excessive aerobic workouts, albeit for a short period.
- Intake of Drugs: Urinary bleeding can also occur due to use of drugs such as the anti-cancer medication Cytoxan/cyclophosphamide; blood thinners like heparin; and anti-coagulants like aspirin.
As discussed above, microscopic hematuria can be caused due to varied underlying conditions. Hence, treatment is dependent on finding the causative disease and then treating it as per standard medical therapies. For example,
- UTIs are treated with antibiotics and other medications.
- Kidney stones may be removed with medicines, shock wave therapy, or surgery.