Blood count: That's what your blood counts

Small and large blood counts are common tests - but for the patient the results are often a mystery. What does it mean when the leukocyte count is elevated? And what are abbreviations such as mcv, mch or mchc? We explain step by step, what is behind the abbreviations in the blood picture and what causes an increased or too low blood value can have. With our help, you can simply read your blood count yourself.

Small blood picture and big blood picture

A blood count is performed in a variety of situations, such as a routine check-up with the family doctor, suspected infection, or surgery. Depending on the situation, either a small or a large blood test is made. A large blood picture consists of a small blood picture and a differential blood picture.

A small blood count determines the concentration of blood cells - red blood cells (erythrocytes), white blood cells (leucocytes), and platelets (thrombocytes). In addition, the concentration of the red blood pigment (hemoglobin) and the hematocrit value are measured. This indicates the proportion of blood cells in the whole blood and thus says something about how thick the blood is. Just a few milliliters of whole blood are enough for a small blood picture.

In case of a large blood count, further blood values ​​will be determined. The differential blood picture, which is done in addition to the small blood picture, provides more accurate information about the different types of white blood cells. In contrast to the small blood count, not only the total leukocyte count is indicated here.

Read the small blood picture correctly

The following overview gives you an overview of the standard values ​​for a small blood test:

Men women
Erythrocytes (RBC or ERY)4.8 - 5.9 million / μl4.3 - 5.2 million / μl
Leukocytes (WBC or LEUK)4 - 10 thousand / μl4 - 10 thousand / μl
Platelets (PLT or THRO)150 - 400 thousand / μl150 - 400 thousand / μl
Hemoglobin (HGB or HG)14 - 18g / dl12 - 16g / dl
Hematocrit (HCT or HKT)40 - 52%37 - 45%

Deviations in the small blood picture

Too high or too low values ​​in the blood test can indicate a disease. However, an elevated or too low blood count alone does not necessarily mean that something is wrong with you.

Below we have listed the most common causes of low or high levels in the small blood picture. If you have any differences, you should always talk to your doctor about it.


Erythrocytes are important for oxygen, but also for carbon dioxide transport in the body. They contain the blood pigment hemoglobin, which binds the oxygen to itself.

  • Value too high: lack of oxygen (due to diseases of the heart or the lungs as well as by staying at altitude), disease of the bone marrow, stress, smoking
  • Value too low: anemia due to blood loss, iron deficiency, vitamin B12 deficiency or folic acid deficiency, celiac disease, kidney damage, infections


Leukocytes are important for our body's defense. They protect the body from pathogens.

  • Value too high: Acute infection with bacteria, fungi or parasites, allergies, bleeding, acute poisoning, shock, leukemia
  • Value too low: viral infection, diseases such as malaria or typhus, over-function of the spleen, damage to the bone marrow (for example, by radiation or drugs in cancer), antibiotic treatment


Platelets play an important role in the blood clotting, an increased or decreased value therefore usually indicates a disturbed blood coagulation.

  • Value too high: High blood loss due to surgery or injury, severe infections, cancers, sports
  • Value too low: Vitamin B12 deficiency, folic acid deficiency, radiation, use of certain medications, alcohol, anemia, malaria

The platelet count may be low even after an increased consumption of platelets. This is the case, for example, with allergies, after infections, with enlargement of the spleen or uncontrolled blood coagulation.


The red blood pigment hemoglobin is responsible in the body for the binding of oxygen and carbon dioxide.

  • Value too high: Increased RBC value, stroke, brain tumor, meningitis, stay at altitude, smoking, fluid loss
  • Value too low: iron deficiency anemia, kidney disease, inflammatory gastrointestinal diseases such as Crohn's disease

In the context of hemoglobin, the following values ​​also play a role:

  • MCV: indicates the average volume of an erythrocyte (MCV = hematocrit / erythrocyte count)
  • MCH: Indicates the average amount of hemoglobin per erythrocyte (MCH = hemoglobin / erythrocyte count)
  • MCHC: indicates the concentration of hemoglobin within the erythrocytes (MCHC = hemoglobin concentration in the blood / hematocrit)


The hematocrit value indicates the ratio between solid and liquid blood components. The higher the value, the thicker the blood and the easier it will be to form clots. An increased value is thus associated with an increased risk for a stroke or myocardial infarction, but also for other heart diseases or diabetes mellitus.

  • Value too high: dehydration, increased proliferation of erythrocytes (polyglobulin)
  • Value too low: anemia, blood loss, overhydration
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