HOW IS THE RED CELL DISTRIBUTION WIDTH CALCULATED? Electronic
instruments are capable of analyzing the blood sample and
detecting the pulses that are produced by red blood cells. The
stronger the pulses are, the greater the red blood cells are in
size. Likewise, the weaker the pulses are, the smaller the red
blood cells are in size. WHAT IS THE NORMAL LEVEL OF THE RED
CELL DISTRIBUTION WIDTH? The normal RDW level is 10.2 to 14.5%.
It is important to keep in mind that the ranges mentioned above
will be different depending on the machine used to do the blood
test. Always use the normal range printed on the lab report to
decide what range is normal. "Where Medical Information is Easy
to Understand"™ WHAT CAN CAUSE THE RED CELL DISTRIBUTION WIDTH
TO BE TOO HIGH? A high RDW (over 14.5%) means that the red blood
cells vary a lot in size. There are many possible reasons why
the RDW level can be too high. To determine what the possible
cause of a high RDW level is, a comparison is made to the mean
corpuscular volume