The leukocytes, or leukos for short, are also called white blood cells because of their color. Because, unlike erythrocytes, they do not transport any red blood pigment. The leukocytes are an important part of the immune system and, so to speak, the "health police" in the body.
- The white blood cell count can indicate infections, but also cancer.
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Bacterial infections, cancers such as leukemia, but also stress can lead to high levels of leukocytes. If there are viral infections, blood formation disorders or certain autoimmune diseases, the leukocyte values can drop.
At a glance:
White blood cells in the blood: This means high and low values
Functions and forms of leukocytes
Leukocytes use the blood as a means of transport and, as part of the immune system, constantly patrol the organism in search of foreign bodies and pathogens such as viruses, bacteria, fungi, toxins and diseased or degenerate cell structures such as tumor cells.
The white blood cells can penetrate various organ tissues as "killer cells" and exercise their guardian function there. Thanks to their surface structure, the leukocytes recognize foreign structures, they can attach themselves to them, mark them and destroy them.
Depending on their role in the immune system, the leukocytes are divided into different groups. The leukocytes include:
- dendritic cells
- neutrophils
- Monocytes (macrophages) = phagocytes
The largest group of white blood cells is made up of neutrophils (or neutrophils) with a share of around 60 percent.
The amount of the individual types of leukocytes can be precisely determined in the differential blood count. To do this, a drop of blood is spread on a small glass plate. The number, distribution and condition of the individual cells are then examined under the microscope.
A leukocyte usually has a rounded shape, depending on the type, it is between seven and 20 micrometers in size. For comparison: a red blood cell has an average size of 7.5 micrometers. The surface of the white blood cells is structured, depending on the task, in such a way that specific foreign structures can be recognized, marked or transported and "disposed of".
The leukocytes are initially formed in the stem cells in the bone marrow. Depending on the task in the lymph nodes, the spleen, tonsils or bone marrow, this starting cell then receives its final shape. A leukocyte is viable between a few hours and several weeks or months. Then their remains are broken down in the respective tissue or excreted in the urine via the kidneys.
Why and how is the white blood cell count determined?
The white blood cell count in the blood or urine is an important one Indicator of inflammatory processes in the body and shows how intact the immune system is. White blood cells can be determined in whole blood and urine.
In addition to the optical test, a test strip is usually used for a quick test in medical practices. These test strips are also available from pharmacies for use at home. This not only allows you to determine and control leukocytes, but also other values in the urine (such as glucose, pH value, protein). However, such self-tests should not replace a visit to the doctor.
Normal value for leukocytes
In healthy adults, there are between 4,000 and 10,000 leukocytes per microliter of blood. In children and adolescents, the white blood cell count is significantly higher – the immune system has a lot more to do during physical development. Up to 30,000 per microliter of blood are normal for newborns and up to 15,000 for school children.
Too many white blood cells in the blood
If the blood count shows too high a number of white blood cells (leukocytosis), it could indicate an infectious disease, leukemia or inflammation in the body. The leukocyte count is also increased during exercise, smokers and during pregnancy. Certain drugs can also increase the number of white blood cells in the blood. These include, for example, preparations containing cortisone or drugs against epilepsy.
White blood cell counts too low
If there are too few leukocytes, doctors speak of leukopenia. Causes can be autoimmune diseases, cancers, diseases of the bone marrow and viral infections. Pain medication, drugs for rheumatism and some antibiotics also reduce the number of leukocytes.
As part of chemotherapy, drugs can deliberately be used that switch off or reduce the function of the bone marrow and thus enormously reduce the number of leukocytes.
If there are too few leukocytes in the blood, the organism is more susceptible to infections in the mouth, throat, nose, ears, lungs and skin. The lymph nodes can also swell.
Leukocytes in urine: causes and treatment in leukocyturia
A certain amount of leukocytes in the urine is quite normal. Because the white blood cells are also excreted via the kidneys and bladder. If the white blood cell count is high, the urine is cloudy. If more than ten leukocytes per field of view can be seen in microscopy, doctors speak of leukocyturia.
If there are high levels of leukocytes in the urine, this is a clear sign of a (bacterial) infection, for example of the kidney or bladder. Treatment of such inflammation of the urinary tract is often done with antibiotics. This will also increase the level of white blood cells in the urine.
In men, a possible cause of excessive leukocytes in the urine is prostate disease. In women, vaginal discharge can lead to increased levels of leukocytes in the urine.
In the case of leukocyturia without an increased number of bacteria in the urine (bacteriuria), infections with chlamydia, trichi-lemonade or fungi are also possible causes. Such an abacterial leukocyturia can in rare cases also be an indication of tuberculosis.
Blood count: important values and what they mean
