Does a high white blood cell count mean i have cancer?

Not necessarily: White blood counts can be elevated as a result of an infection or inflammatory process. When this happens it is called a leukemoid reaction and is a normal physiologic response.

Not necessarily: While high WBC count is associated with leukemia infections are more commonly associated with high WBC count.

Not necessarily: Many conditions such as infection, inflammatory process, infarction can increase white blood cells count. This is a normal body response. However, if white blood cell counts persistently elevated in the absence of infection/inflammation &/or if it is associated with abnormality on the other blood counts-red blood and platelets -further evaluations including bone marrow biopsy is likely needed.