Blood Cylinders

Blood casts are pathological formations in the urine, consisting of accumulations of erythrocytes (red blood cells) and their membranes.

They are formed in the renal tubules and are excreted in the urine in various kidney diseases accompanied by bleeding into the urinary tract (hematuria).

The presence of blood cylinders in the urine always indicates a pathological process in the kidneys and requires additional examination to determine the cause.

The main reasons for the appearance of blood casts include:

1. Acute and chronic glomerulonephritis

2. Pyelonephritis

3. Kidney tuberculosis

4. Tumors of the kidneys and urinary tract

5. Kidney injuries

6. Stones in the kidneys and ureters

Detection of blood cylinders during urine microscopy helps the doctor make a preliminary diagnosis and prescribe additional tests (general urinalysis, biochemical blood test, ultrasound of the kidneys, etc.) to clarify the nature of the kidney disease and select adequate treatment.

Blood casts (erythrocytes) are specific cells that are formed when blood appears in the urine. They consist of erythrocytes - red blood cells containing hemoglobin, which is responsible for transporting oxygen in the human body. These cells are surrounded by a membrane of plasma and proteins that protects them from destruction and maintains their shape. Cylindrical cells are formed as a result of the destruction of some red blood cells, and the rest form structural components.

Typically, the blood casts are the size of a bacterial cell and look like drops of milk or lemon juice. Their number and size may vary depending on the degree of hemolysis (destruction of red blood cells). When small in number, the renal tubules have the ability to completely absorb all the casts and residual traces caused by glomerular hemorrhage in the glomeruli. The presence of casts in the kidneys is considered a manifestation of nephrotic syndrome. High cast counts are also observed in patients with hepatitis or nephrotic syndrome caused by acute infection. The normal content of red blood cell casts is from 20 to 150 units in one microliter of urine. Measuring their content may be one of the methods for assessing bleeding in the urinary tract.

When a large number of blood cells enter the urine, the cylindrical shape does not have time to form. Such cells can move freely throughout the urinary system, irritate the walls of the bladder when removed, or damage its capillaries. The cylindrical shape is the main one for hemolysis - the breakdown of red blood cells in the blood serum. In healthy people they are absent and are detected by microscopy. If a circulatory disorder begins in the hemodynamic system, then with excessive destruction of the formed elements, red blood cells acquire only a cylindrical shape, which characterizes the condition of the body as serious and dangerous.