 [ Symptoms ] what causes wbc to be high for over a years time [ Disease ] well a number of things can cause the white blood count to be high over a long period of time it is important to define high  though in general a high white blood count number might be defined as 10  i am not going to go into all the specifics of what that number refers to  but a wbc result of 11 may be no cause for alarm and some people naturally have higher or lower results for various blood tests for example if a person always tests at 10 5 for wbc we say they live at that number in other words that number is normal for them other things that can cause a wbc number to be high are a chronic infection certain vitamins or herbs certain diets and other things if you have consistently had a high white blood cell count but your health care provider is not concerned i would suggest asking him or her about it if you test was borderline high such as 10 10 5 or 11 your provider may feel you simply have a naturally robust white blood cell count i hope this helps