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Erythrocytes in urine: symptoms, consequences, diagnosis
Last reviewed: 04.07.2025

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The clinical picture when red blood cells appear in the urine is usually caused by the underlying pathology.
The patient may complain of a change in the color of the urine - this is possible in the case of severe erythrocyturia. The color may change:
- only at the beginning of the urination process (if the initial section of the urethra is affected);
- only at the end of the urination process (in case of damage to the prostate gland, cervical part of the bladder, internal urethral opening);
- in the entire volume of urine (in case of pathologies of the bladder, ureters, renal pelvis or renal parenchyma).
Complaints of pain usually accompany urolithiasis, cystitis, uric acid crisis. In other cases, there may be no pain. The greatest danger in this case is tumour processes in the bladder and kidneys: in such cases, erythrocytes are often found in the urine without symptoms, and pathologies are found only during a random (for example, routine) examination.
Symptoms such as fever and red blood cells in the urine are common to many genitourinary infections. To make an accurate diagnosis, the doctor must evaluate the entire clinical picture and perform additional diagnostic procedures.
When kidney function is impaired, the body does not remove water and salts well, which causes swelling. Swelling occurs in the morning – in the form of swollen eyelids and bags under the eyes; by evening, this symptom usually disappears. Red blood cells in the urine and swelling with morning frequency are a sure sign of kidney problems. Heart diseases are characterized by “lower” and “evening” swelling, when fluid accumulates closer to the second half of the day in the lower extremities (mainly in the ankles and feet).
What does a red blood cell look like in urine?
Red blood cells in urine with an isotonic reaction look like yellowish or red discs, concave from two planes. If the environment is hypotonic or alkaline, then the erythrocytes can increase in size and be almost colorless - in medicine, such structures are called "erythrocyte shadows". In acidic conditions or concentrated urine, they acquire uneven borders and become wrinkled. Normal and altered erythrocytes in urine are well visualized using the phase-contrast microscopic method.
As we have already said, the norm is considered to be when there are no red blood cells in the urine, or their number is 1-2 or three in the field of view. In any case, such a line in the analysis result as "red blood cells in urine 1, 2, 3, 5, 10 and more" should be alarming. It is possible that the doctor will advise to undergo the examination again.
Red blood cells in urine sediment are:
- Altered or leached erythrocytes in urine – without hemoglobin, discolored, single or double contoured, reduced in size (compared to normal erythrocytes). Such structures are often found in urine with low relative density, in an acidic environment (at pH 5-6), or when they remain in urine for a long time.
- Unchanged erythrocytes in urine – with hemoglobin, having a disc-shaped form (possibly a lens shape, concave from two planes). Such structures are characteristic of a weakly acidic, neutral or alkaline environment.
In terms of morphology, red blood cells may differ depending on which part of the urinary tract they come from. For example, in renal pathologies, these cells are dysmorphic (against the background of a large number of red blood cells, they can be both dysmorphic and unchanged).
Unchanged, or so-called fresh, red blood cells in the urine indicate damage to the urinary tract – for example, the bladder or urethra.
Dysmorphic erythrocytes in urine appear in case of a disrupted filtration process in the renal filter (with excessive permeability). A high level of dysmorphic cells indicates mainly a renal etiology of the disease.
However, the main sign of kidney problems is considered to be when protein, red blood cells and casts are present in the urine at the same time.
Flat red blood cells in the urine may indicate a pathology of the urinary system, accompanied, for example, by iron deficiency anemia or other types of anemia.
Leukocytes and erythrocytes in urine are detected against the background of infectious diseases, as well as with pyelonephritis, prostate or bladder tumors, connective tissue diseases, and even during exacerbation of pancreatitis or during fever. Since there can be many reasons for the problem, it is recommended to retake the urine test, as well as additionally conduct a study according to Nechiporenko.
Protein and red blood cells in urine may appear temporarily - this happens during intense physical overload, severe stress or hypothermia, allergic process. During pregnancy, such a combination of unfavorable indicators is observed due to mechanical pressure on the kidneys (as a rule, this can be determined in the later stages). But such a violation is also detected in other serious diseases, so you cannot do without high-quality diagnostics here.
Red blood cells and hemoglobin in urine are most often found when blood enters the urinary tract - for example, against the background of glomerulonephritis, inflammatory diseases, tumors. Hemoglobin without red blood cells in urine is found as a result of the destruction of the latter inside the vessels. This is typical for hemolytic anemia and is possible with intoxication, diseases of the spleen, allergies, infectious processes, injuries. The listed diseases are characterized by an increased level of hemoglobin in the blood plasma: due to excess protein, it overcomes glomerular filtration and enters the urine. This condition is considered quite dangerous and can be complicated by renal failure.
Both red blood cells and hemoglobin can be detected in the urine of athletes: this phenomenon is temporary and is not considered a pathology.
Bacteria, leukocytes, and erythrocytes in the urine indicate a probable infectious lesion of the urinary organs. But it should be taken into account that bacteria often get into the urine fluid during improper analysis. Therefore, it is always recommended to re-submit the urine.
The presence of salts in the analysis in large quantities also helps to make a preliminary diagnosis. If a small amount of salts is detected, this is not considered a pathology and may indicate some features of the patient's diet.
Urate salts and erythrocytes in the urine against the background of an acidic reaction indicate the possible presence of urate stones, an excess of animal proteins in the diet, and severe intoxication in the body.
Oxalates and erythrocytes in urine are found in people who eat a lot of foods with a high content of oxalic acid. This is also possible with the formation of oxalate stones, diabetes, chronic intestinal pathologies, pyelonephritis.
Phosphates and erythrocytes in the urine against the background of an alkaline reaction indicate the presence of phosphate stones in the urinary system, which are formed when phosphate metabolism in the body is disrupted (sometimes found in adherents of a strict vegetarian diet).
Renal epithelium is usually not detected in the urine of healthy patients. Epithelium and erythrocytes in the urine may be present in inflammatory pathology affecting the renal tubules, as well as in glomerulonephritis.
Another possible component detected in urine is bilirubin. This is a bile pigment that is formed with the destruction of red blood cells and the breakdown of hemoglobin. This component is usually present in the analysis in minute quantities that cannot be determined. Red blood cells and bilirubin in urine in large quantities can be detected in tumor processes, liver cirrhosis and hepatitis.
It is important to correctly correlate the results of two general tests - blood and urine. For example, erythrocyturia often occurs simultaneously with signs of an inflammatory process or anemia. And eosinophilia and erythrocytes in the urine may indicate the presence of non-atopic dermatological diseases, rheumatism, allergic processes. However, in some cases, such a combination also occurs after long-term use of acetylsalicylic acid or some injectable antibiotics.
Many red blood cells in the urine are observed against the background of infectious, traumatic, autoimmune, toxic, tumor and mixed factors. A strong increase in the indicators as a result of the analysis can seriously frighten the patient: all red blood cells in the urine most often indicate the development of bleeding in the genitourinary system, which can be related to both injuries and tumor processes. It is possible to make a correct diagnosis even after a thorough survey of the patient, collection of complaints, clarification of the nature of the pathology.
Single red blood cells in the urine – namely 1, 2 or 3 – are considered normal and do not require any medical intervention. The same can be said if traces of red blood cells are found in the urine: in some cases, at the discretion of the doctor, a repeat test may be recommended.
Diagnostics red blood cells in the urine
If red blood cells are found in the patient's urine, the doctor must conduct a number of additional examinations. First of all, the patient is questioned and examined, the abdominal cavity is palpated. For men, it is important to do a rectal examination to detect enlargement or inflammation of the prostate. For women, a gynecological examination is relevant.
In addition, the patient is examined for enlarged lymph nodes, the presence of hemorrhages, petechiae, etc.
The determination of red blood cells in urine is carried out microscopically, during a general analysis – one of the most common diagnostic studies. Such an analysis can be prescribed for most diseases. It includes the determination of up to two dozen indicators – including the presence and quantity of red blood cells.
Urine tests are mandatory: the presence of protein, morphology of red blood cells are studied, the presence of leukocytes and cylinders is checked.
Microscopic examination of urine sediment helps to detect:
- presence of unchanged red blood cells;
- the presence of altered erythrocytes (characteristic of glomerulonephritis) and erythrocyte casts.
Additionally, urine fluid is cultured (if an infectious process in the urinary tract is suspected). If tuberculosis of the urinary tract is suspected, such culture is repeated three times.
Urine sediment cytology is indicated if there is reason to suspect a tumor in the lower urinary tract. In case of malignant processes in the kidneys, such a procedure is uninformative.
A general blood test with ESR calculation, determination of blood urea nitrogen, and serum creatinine are routinely prescribed. If glomerulonephritis is suspected, then it is advisable to evaluate the antistreptolysin O titer, with the level of complement components in the plasma.
Instrumental diagnostics are primarily represented by methods of excretory urography and ultrasound examination of the right and left kidneys (the lower urinary tract is not examined using ultrasound due to its low information content).
The following may be recommended as auxiliary procedures:
- computed tomography;
- renal angiography;
- ascending pyelography;
- urethroscopy, cystoscopy;
- renal tissue biopsy (especially indicated when altered red blood cells are detected in the urine).
Differential diagnosis
Differential diagnostics of the appearance of red blood cells in urine is carried out with the following diseases:
- urinary tract infections (cystitis or urethrotrigonitis in female patients, urethritis or prostatitis in male patients);
- urolithiasis (formation of stones in the kidneys, bladder, ureters);
- vascular pathologies (renal vein thrombosis, renal infarction);
- tumor processes (oncology of the kidney, renal pelvis, ureter, bladder, prostate);
- infectious processes (tuberculosis, malaria, endocarditis);
- glomerulonephritis;
- damage to dilated vessels against the background of prostate adenoma;
- necrotic processes in the renal papillae.
It is also necessary to take into account the possibility of blood pathologies, which may cause bleeding, as well as hematuria during physical exertion.
More rare pathologies that also require differentiation include renal polycystic disease, urinary endometriosis, schistosomiasis, hemorrhagic and systemic vasculitis.
Complications and consequences
The probability of developing adverse effects and complications against the background of the appearance of red blood cells in the urine depends not on the specific fact of their detection, but on the initial cause of the disorder. Thus, complications can develop in the absence of treatment for pyelonephritis, urolithiasis, etc. Erythrocyturia itself is only a symptom, not a diagnosis, therefore, determining the consequence of a symptom is, at the very least, inappropriate.
In any case, the presence of red blood cells in the urine requires further examination to identify the underlying pathologies. And only on the basis of the established final diagnosis can we make predictions about possible complications.
Prevention
It is impossible to determine specific prevention of the appearance of red blood cells in urine, since the development of the disorder occurs for many reasons.
To avoid the problem, you need to follow these recommendations:
- avoid hypothermia, especially in the lower back, abdomen and groin area;
- establish for yourself the correct diet, which will help prevent the development of urolithiasis and intoxication;
- drink enough fluids daily;
- avoid excessive physical exertion;
- avoid injury to organs located in the abdominal cavity.
You should visit your doctor periodically for routine preventive examinations.
Forecast
When red blood cells are found in the urine, it is quite difficult to immediately determine the severity of the disorder: the nature of the consequences depends on the severity of the disease that caused it.
In most cases, isolated erythrocyturia has a favorable prognosis. Unfavorable cases are those when erythrocytes in the urine are present against the background of proteinuria or nephrotic syndrome, systemic lupus erythematosus, Alport syndrome, extracapillary or tubulointerstitial nephritis, renal polycystic disease, tuberculosis, tumor processes, IgA nephropathy with nephrotic syndrome and increased blood pressure.