Causes of elevated red blood cells in urine

Laboratory test results often raise many questions for patients. This is especially true when blood elements appear in fluids where they should not normally be – for example, if red blood cells are found in urine. This condition is called erythrocyturia and is a variant of hematuria.

The term " hematuria " literally translates as "blood in the urine" and means the presence of not only red blood cells but also other blood elements. That is why erythrocyturia is designated as a separate term. Does it indicate serious health problems?

What does it mean?

Red blood cells are responsible for oxygen transport, and their norm in urine is no more than three or four in the field of vision. Exceeding this norm is called erythrocyturia, or hematuria (if, in addition to red blood cells, other components or blood cells are found in the urine).

A common factor that contributes to the occurrence of such a malfunction is considered to be an infectious process in the urinary tract, or a tumor process. But a correct diagnosis can only be made after a comprehensive assessment of the results of laboratory tests, instrumental diagnostics, as well as information obtained during the study of the patient's medical history.

The presence of a large number of red blood cells in the urine is often caused by mechanical damage, such as trauma. In women, blood can get into the urine during menstrual bleeding.

In healthy people, urine analysis does not reveal any red blood cells at all, or 1-2 during microscopic examination.

If more than one or two red blood cells are found in the morning urine, the doctor may prescribe additional testing, for example, urine collection according to Nechiporenko.

The norm of red blood cells in the urine analysis according to Nechiporenko is no more than 1000/ml. A larger number of them allows us to suspect such pathologies as the presence of stones in the kidneys or bladder, polyposis, tumor processes, purulent cystitis, heart disease, hypovitaminosis C, systemic lupus erythematosus, etc. The final diagnosis is determined only by a doctor, focusing on both the test results and the indicators obtained during other diagnostic measures.

Causes of the appearance of red blood cells in urine

Red blood cells are blood cell structures that deliver oxygen to the body's tissues. In theory, they should not be present in urine at all. However, as practice shows, a small number of these cells sometimes appear in the field of vision. This is due to a small leakage of red blood cells through the kidney membrane or vascular walls. If this number exceeds the norm, then one can think of both the onset of an inflammatory reaction in the urinary tract or kidneys, and of traumatic injuries, tumor processes, stones.

If renal function is impaired, then erythrocytes in the urine are found in pyelonephritis, amyloidosis, glomerulosclerosis, nephropathy, glomerulonephritis.

Glomerulonephritis is often the reason for patients to seek medical attention: the acute form of the disease begins with pain, increased urination, and changes in the color of the urine. Only after a urine analysis is the presence of red blood cells detected.

The cause of erythrocyturia in pathology of the urinary system is often cystitis, urinary diathesis, tumors, mechanical damage (for example, after some medical procedures).

Kidney stones or bladder stones can injure the mucous membrane of the urinary system from the inside, which can also cause red blood cells to appear in the urine. Most often, this is observed during an attack of stone movement, but in some cases, erythrocyturia is possible outside the period of exacerbation. It has happened that even sand in the kidneys led to microhematuria: everything depends on the component composition of the stones, the size and shape of the grains of sand, as well as the general condition of the kidneys and urinary system.

During treatment with nonsteroidal anti-inflammatory drugs, sulfonamides, glucocorticoids, and after antibiotics, erythrocytes can also be detected in the urine. This happens especially often after a course of treatment with aminoquinolines - for example, Chloroquine, Delagil. In most cases, this is due to increased permeability of the vascular walls, the development of post-drug vasculitis.

In some cases, the problem may arise when administering oral dehydration fluids. For example, red blood cells in the urine after rehydron may appear due to impaired renal function, or if the drug was administered too quickly.

In prostatitis, erythrocytes in the urine are determined relatively rarely, and this is considered an indirect sign of the onset of complications. Thus, an inflammatory disorder of the gland structure with damage to part of the blood vessel, or hyperplasia, or a malignant tumor process is possible. The exact cause should be determined by a doctor.

In women, during menstrual bleeding and even before menstruation, blood elements may get into the urine during its collection if special rules are not followed. In general, closer to the beginning of menstruation, it is not recommended to take a urine test at all, since the results obtained as a result may be significantly distorted. But there are cases when the test must be taken urgently. Then you will have to adhere to the following rules:

• perform a high-quality wash;
• insert a vaginal tampon to prevent blood from getting into the urine;
• begin urinating, collecting only the middle portion of urine in a sterile container.

To avoid errors, it is recommended to repeat the test a few days after the end of the monthly bleeding.

As for tumors, they can appear in any organ of the genitourinary system. The leading sign that allows one to suspect a tumor process is the detection of blood elements, and in particular, red blood cells in the urine. In cancer, hematuria can be both pronounced and hidden, and can periodically appear and disappear. In such a situation, it is very important to conduct a cystoscopy in a timely manner to determine the source of bleeding.

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Risk factors

Often, medical professionals mention factors that increase the risk of developing a particular disease. There are such factors in terms of the appearance of red blood cells in the urine.

• Age factor and gender. Men over fifty are mostly at risk (primarily due to frequent complications of prostate diseases).
• Recent infectious disease. Viral and bacterial infections increase the likelihood of kidney complications, and as a result, red blood cells may appear in the urine.
• Hereditary predisposition. There are “family” histories of diseases associated with urolithiasis or renal pathologies.
• Regular medication intake, tendency to self-medicate. Many antibiotics (for example, penicillin series), non-steroidal anti-inflammatory drugs and other drugs can increase the risk of red blood cells appearing in urine.
• Excessive physical activity. Physical activity, especially prolonged exercise, can cause changes in urine test results: for example, microhematuria is common in long-distance runners.

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Pathogenesis

Let's consider the main pathogenetic factors for the appearance of red blood cells in urine:

• Mechanical damage, destruction of tissues of the urinary system (cancerous process, abscess, necropapillitis, tuberculosis).
• Increased pressure in the renal vein (formation of a thrombus in the renal veins).
• Violation of the integrity of the basement membrane (immune or metabolic etiology of damage - for example, in glomerulonephritis, renal amyloidosis, diabetic glomerulosclerosis).
• Coagulating processes inside the renal vessels (in periarteritis nodosa, lupus nephritis, thrombocytopenic purpura, hemolytic uremic syndrome),
• Congenital disorder of the glomerular basement membrane (eg, in Allport syndrome).
• Toxic or inflammatory reaction of the interstitium (in interstitial nephritis, hemorrhagic fever against the background of renal syndrome).

Pathologically, the appearance of erythrocytes in urine may be accompanied by inflammatory processes, deposition of amyloid masses, thickening of the glomerular basement membrane, or its specific changes, and expansion of the mesangium.

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