Leukocytosis

• A high white cell is known as leukocytosis and can be caused by a wide range of pathological processes. Important factors in determining the cause of leukocytosis include the rate of the white cell count rise and which type of white cell(s) are raised. Neutrophils and lymphocytes make up the majority of the white cells in the blood, so these two cell types are usually the cause of a raised total white cell count.
• Causes of leukocytosis:

  Acute:

  ·       Reactive: infection, inflammation, post-surgery

  ·       Steroids: stress response (i.e. endogenous steroids) or medication (i.e. exogenous steroids)

  ·       Haematological: acute leukaemias

   

  Chronic:

  ·       Reactive: chronic infection, smoking

  ·       Haematological: leukaemia, certain subtypes of lymphoma

  ·       Hyposplenism: typically mild

  ·       Pregnancy