Platelet count:The calculated number ofplateletsina volume ofblood, usually expressed as platelets per cubic millimeter (cmm) of whole blood. Platelets are the smallestcell-like structures in the blood and are important for blood clotting and plugging damaged blood vessels.Plateletcounts are usually done bylaboratorymachines that also count other blood elements such as the white and red cells. They can also be counted by use of amicroscope. Normal platelet counts are in therangeof 150,000 to 400,000 per microliter (or 150 - 400 x 109perliter). These values many vary slightly between different laboratories.
