Why are reticulocytes counted?
Reticulocytes are red blood cells that have just emerged from the bone marrow. Their number indicates whether the bone marrow is responding to anemia. In iron deficiency or B12 deficiency anemia, production is reduced and there are few reticulocytes; with blood loss and hemolysis, the bone marrow works to the limit and their number increases sharply. The indicator is also indispensable for monitoring treatment: the growth of reticulocytes 5–7 days after the start of taking iron supplements confirms that the diagnosis and therapy have been chosen correctly.
Why preparation is so important
The laboratory result is a number, but the correct number can only be obtained if the rules are followed. Eating changes the levels of glucose, lipids and a number of enzymes significantly; physical activity the day before increases CK and AST; smoking affects hormones; time of day is critical for cortisol and testosterone.
Therefore, a “bad analysis” often turns out to be a consequence of impaired preparation, and not an illness, and leads to unnecessary examinations and prescriptions.
General rules for donating blood
- on an empty stomach 8–12 hours, you can drink water
- Eliminate alcohol and intense exercise per day
- no smoking in an hour
- donate blood before physiotherapy, x-rays and massage
- Take medications in advance by agreeing with your doctor
- for hormones in women, take into account the day of the cycle
How to read the result
Reference values depend on the method and equipment of the laboratory, so it is correct to compare results only within the same laboratory. A deviation of a few percent from the normal limit in itself rarely matters - the overall picture and dynamics are important. It is up to the physician to interpret the analysis: an isolated indicator without a clinical context is often misleading.