PREANALYTICAL AND ANALYTICAL FACTORS AFFECTING LABORATORY RESULTS

The results of laboratory tests have a substantial role in the diagnos tics of diseases. However, laboratory results do not always correspond with the patient's clinical status. They may be unexpected and surpri sing. On the other hand, an abnormal laboratory result may be accepted as such and interpreted as a sign of a disease. However, an abnormal result may result from several factors other than disease. Conventiona lly, these interfering factors have been divided into preanalytical an d analytical factors and furthermore into factors acting in vivo and i n vitro. The list of these factors is long and laborious to bear in mi nd. In this review we focus on the factors which, in practice, most of ten affect laboratory results in healthy individuals and which explain an unexpected result.