Hematocrit levels can affect results whether the sample is obtained from a forearm or a finger stick. Hematocrit levels less than 30% may cause falsely high readings and hematocrit levels greater than 55% may cause falsely low readings. If the patient does not know their hematocrit level, they should consult their healthcare professional. Hematocrit levels may be affected by too much kneading during puncture site preparation.