Is this blood test normal?

Laboratory results: the blood sample

Before each blood sample is taken, the attending physician must carefully make a selection from the large number of laboratory tests available - there are actually thousands of different parameters in blood and other body fluids. This depends on the respective medical question (indication).

A blood sample can be drawn for the following reasons:

  • Preventive medical check-up,
  • Clarification (confirmation or exclusion) of a suspected diagnosis,
  • Follow-up in case of confirmed disease
  • Assessment of the success of the therapy,
  • Assessment of the further course of the disease (prognosis).

Many mistakes happen in the run-up to the laboratory analysis. These steps are known as “preanalytics”. The most common mistake is mixing up samples. This can happen if, for example, the tubes are labeled incorrectly when taking a blood sample.

A few points must be observed even before the blood sample is taken so that correct and coherent (plausible) test results are obtained in the end:

  • When to take blood: ideally in the morning between 7 a.m. and 9 a.m.
  • For certain examinations, the patient should be fasted (e.g. blood sugar test): But fasting does not mean starving! The day before, nothing should be eaten after 8 p.m. Small amounts of water or unsweetened tea may be drunk on the morning of the blood draw.