In some anemias, such as pernicious anemia, the amount of variation (anisocytosis) in RBC size (along with variation in shape - poikilocytosis) causes an increase in the RDW.   The CBC is used as a broad screening test to check for such disorders as anemia, infection, and many other diseases.
Obtaining a Travel Authorization Number A Travel Authorization Number (T-Number) is required for those employees where a local rule applies and for all non-employee travel. It is needed for all travel involving an overnight stay or the purchase of an air, rail, or bus ticket.
Make an appointment to apply at a passport agency or center by calling 1-877-487-2778 or 1-888-874-7793 (TDD/TTY). Fill out your application and collect your documents, including proof of international travel. More more information, see How to Apply.