Article overview urine sediment
- What is urine sediment?
- When do you examine the urine sediment?
- Assessment of cells and cylinders
- Assessment of other sediment components
- What to do if you have a noticeable urinary sediment?
What is urine sediment?
The urine sediment is the urinary solids, ie various cells and cell components. The doctor examines the urine sediment under the microscope and can thus find important information on the presence of urinary tract diseases.
What does the urine sediment usually consist of?
The following components are normally found in urine sediment up to a certain amount:
- white blood cells (leukocytes)
- red blood cells (erythrocytes)
- shed epithelial cells from the urinary tract
The following quantities of the different components are considered normal:
0 - 5 / μl (0-2 pieces in the visual field)
0 - 3 / μl (<5 in the field of view)
Cylinders are cylindrical structures of protein - clumped outlets of the smallest renal tubules. Depending on which other components such a protein cylinder, the doctor distinguishes different types of cylinders.
How is the urine sediment made?
To obtain the urine sediment, the doctor needs a sample of fresh midstream urine (about 10 ml). Ideally, this comes from the morning urine. This urine sample is centrifuged for up to ten minutes. As a result, the solid components settle on the bottom of the sample tube. Using a pipette, the doctor drips a small amount of the sediment onto a glass slide and covers it with a coverslip. Afterwards he can judge the urine sediment under the microscope.
The urine sediment evaluation should be carried out not later than two hours after the sampling.To the table of contents
When do you examine the urine sediment?
The doctor examines the urine sediment in the following cases:
- Suspected urinary tract infection, for example pain in urination or in the bladder region
- Suspected inflammation of the prostate (prostatitis), for example, pain in urination or defecation
- Clarification of kidney stones
- Clarification of blood or protein in the urine (hematuria or proteinuria)
- other kidney and urinary tract disorders
Urine sediment: assessment of cells and cylinders
First, the doctor gets a first overview of the urine sediment with a weak magnification on the microscope. After that, he sets a larger magnification and now counts the individual cells. The type and number of different cell types already allow conclusions about certain urinary tract diseases:
For example, an increased number of red blood cells (erythrocytes) in the urine sediment may indicate an infection or injury to the urinary tract, urinary stones, or tumors of the kidney or urinary tract. In women during menstruation, blood in the urine may also be just a sample contaminant.
If white blood cells (leukocytes) are increasingly found in the urine sediment, there may be inflammation of the kidneys, urinary tract or, in the case of men, the prostate. Also rejection reactions after transplantation as well as allergic reactions may be the reason for an increased leukocyte count in the urine.
Sometimes so-called acanthocytes appear in the urine sediment - abnormally altered erythrocytes with pointed protrusions. Then there may be a glomerulonephritis behind it, so an inflammation of the renal corpuscles.
Increased squamous epithelia in the urine are usually due to an "impurity", such as with vaginal secretions. This often happens when the urine sample is not from the midstream urine.
In addition to the cells, the doctor also assesses the cylinders in the urine sediment. For example, granular cyclins may be present in all acute and chronic kidney diseases, especially in glomerulonephritis. Slightly yellowish wax cylinders are found in the urine sediment of people with severe chronic kidney weakness. Hemoglobin cylinders occur when red blood cells disintegrate (such as in dialysis patients), myoglobin cylinders in severe muscle injuries.To the table of contents
Urine sediment: assessment of other sediment constituents
In various diseases, besides cells and cylinders, there are also other components in the urine sediment, for example:
- Bacteria in urinary tract infections
- Parasites such as trichomonads (trigger of the sexually transmitted disease trichomoniasis)
- Worm eggs, such as the squirrel leeks (Schistosoma) - the causative agents of schistosomiasis (schistosomiasis))
- different crystals in kidney stones (for example, calcium oxalate stones or uric acid stones)