Dorothy FarrarBlood test
A blood test ( blood count ) gives a lot of information about how healthy the body is and whether all organs are functioning properly. The blood sample taken is examined in a medical laboratory and the values desired by the doctor are determined.
What is a blood test (blood count)?
For a blood test, arterial (from an artery), venous (from a vein), or capillary (from a small blood vessel) blood is taken from the patient.
Venous and arterial blood is obtained by puncturing a vein or artery with a cannula; capillary blood exits by cutting a well-perfused area, such as the earlobe or a fingertip.
Depending on which health questions are to be clarified, certain tests are carried out with the blood. For example, there is the large and the small blood count, the determination of the blood sedimentation rate or the analysis of the blood gases.
The blood test can also be used to determine the blood group, discover antibodies or locate bacteria and viruses . Whole blood, i.e. blood in its entirety, is not usually used, but the separate components of the blood are examined.
What is a blood test for?
A blood test is used for diagnostics, provides information about the course of an illness and about the healing process. It is carried out during normal routine examinations and when diseases are suspected.An inflammation in the body, a deficiency disease such as iron deficiency or a blood disease such as anemia can be ruled out or confirmed with a blood test. A coagulation disorder, which is either congenital or caused by a disease of the liver, can also be detected in the blood.
A blood test shows whether the blood is transporting enough oxygen and can indicate a cardiovascular disease . Cardiac arrhythmias can be caused, among other things, by a too low concentration of potassium in the blood.
If viruses, fungi , bacteria or parasites are suspected, the blood test can provide certainty. Pregnancy can be clearly proven by evaluating a blood sample. It is also possible to clarify functional disorders of the liver, kidneys and thyroid gland with a blood test. Determining enzymes in the blood can be used to diagnose heart disease, muscle dysfunction, digestive disorders or a disease of the pancreas.
What is a blood count?
The blood required for the blood test is taken from the patient and drawn into special blood tubes. They are marked with specific colors and are filled with blood in a predetermined order. These tubes are then shipped to a medical laboratory.
For a blood count, the number of red (erythrocytes) and white (leukocytes) blood cells is determined, as well as the platelets (thrombocytes).
In addition, the proportion of all solid components in the blood (hematocrit value) is determined, as well as the amount of the red blood pigment (hemoglobin). The average volume (MCV) of the red blood cells is measured, as well as the average amount of the blood pigment contained in the red blood cells.
The full blood count also includes examining the white blood cells and their subtypes, as well as checking the shape of the blood cells. The blood count is created entirely by machine.
For other blood tests, such as the blood clotting test, the blood is mixed with a specific substance (citrate). A blood culture is used to detect microorganisms.
To do this, you spread some blood on a bowl coated with a special gel and leave it in a warming container at 37 degrees Celsius. Bacteria or viruses, for example, then multiply in this gel and become visible under the microscope.
read blood count
| Blood count – explanation | ||
| blood value | normal value | explanation |
| Hb value (hemoglobin) | 12-18 g/dl | Amount of red blood pigment: value decreases with iron deficiency |
| erythrocytes | 4,3 – 5,9 Mio./µl | Red blood cells (contain red blood dye hemoglobin): value increases in tumors, various heart and lung diseases; Value decreases with reduced blood formation (e.g. iron deficiency, vitamin deficiency), blood loss (e.g. menstruation, childbirth) |
| leukocytes | 3.800-10.500/µl | White blood cells (defense cells): value increases with bacterial infection (inflammation), leukemia; Value decreases with virus infection (e.g. flu ) |
| blood sugar | 70 – 99mg/dl (fast) | Glucose level: value increases with diabetes (diabetes); Value decreases when the blood sugar control mechanism is disturbed (e.g. due to diabetes, overweight , stress , alcohol) |
| HKT value (hematocrit) | 35-52 Vol% | Measure of the proportion of solid blood components (viscosity of the blood): the value increases when there is a lack of liquid; Value decreases in diseases of the blood |
| blood sedimentation rate (ESR) | Men: <20mm/h; Females: <30mm/hr | Sedimentation rate: Value can increase in the case of inflammation, anemia , pregnancy, menstrual bleeding, among other things |
Risks, dangers and side effects
When taking the blood sample for a blood test, there may be a small amount of bleeding at the puncture site, which then becomes visible as a “bruise”. This depends on the routine of the person taking the blood but also on how easy it is to reach the blood vessel.
Infections are possible, but rather rare these days because sterile disposable material is used. Since only a small amount of blood (minimum 2 ml, maximum 50 ml) is taken for a blood test, this has no effect on the well-being of the patient, as an adult has around six liters of blood in their body.
Hello and welcome to my Health Guide & Encyclopedia! My name is Dorothy Farrar, and I'm the founder and main author of this platform.
My passion for health and wellness started at a young age when I became interested in the connection between the food we eat and the way we feel. This fascination led me to study nutrition and dietetics in college, where I learned about the importance of a balanced diet and the impact of various nutrients on the body.