Q: I am 18 years old. I underwent medical tests in my college, which stated that I have severe eosinophilia. My WBC count was 11,000mm. I don't know what exactly is it. I am a smoker and smoke around 8 cigarettes a day. Is it due to severe smoking? Am I in any kind of danger? What precautions do I need to take?

A:The normal total leukocyte (white blood cells) count varies with the age of a person. It also has a diurnal cycle i.e. counts vary during a 24 hour day. Normally they range from 4000 to 10,000 per ml in an adult. Leukocytosis is an increase above the accepted normal range of total leukocytes. Usually only one type of cell is responsible for this increase, but there may be a simultaneous increase in several cell types. The counts may go up due to an increase in any component of the white cells i.e. neutrophils (called neutrophilia), lymphocytes (called lymphocytosis), monocytes (called monocytosis), eosinophils (called eosinophilia) or basophils (called basophilia). This can be judged by a differential leukocyte count. The range of each of these cells also varies with the age of an individual. There are numerous causes for increases in neutrophils, lymphocytes etc. The degree of leukocytosis depends upon several factors like its cause, severity of the infection, resistance of the body, localisation of the inflammatory process (greater neutrophilic leukocytosis is produced by a localised disease process rather than a generalised one) and modification by treatment. Eosinophils are a type of white blood cells (WBCs) produced in the bone marrow that contain proteins that contribute to the immune response against infectious disease agents and to tissue damage in allergic and autoimmune diseases. Normally, the absolute eosinophil count in the blood is around 500 per microlitre but it can increase in: allergic conditions (asthma, allergic rhinitis, drug reactions), infectious diseases (especially worm infestation), some connective tissue diseases, malignancies etc. The elevated TLC needs to be viewed in the light of the clinical profile. This would help decide if further investigations are warranted and the appropriate therapy.