I am a 26yr.old female and recently i was told both my red and white blood cell counts were high what would be common causes?

Need more info: How high are the counts? Do you have any symptoms? Depending on the levels these may be within normal limits. It would be useful to discuss the results with your doctor.

Polycythemia.: Too many red blood cells is called polycythemia. It can be primary (a blood disorder) or secondary (a problem with oxygen delivery, such as lung disease, congenital heart or hemoglobin issues, smoking, etc.). The blood disorder polycythemia vera also includes high white counts, as do some secondary causes. See a hematologist.