TLC Decreased

Leukopenia in

Some bacterial infections (e.g. typhoid), 
viral or protozoal infection, 
bone marrow depression and 
starvation and 
physiological at night. 

TLC Increased

Leukocytosis in

Any acute/ chronic pyogenic or pyogenic (fever producing) infection, 

leukemias, 

physiological in newborns, 

after exercise, 

in evenings, 

epinephrine injection, 

stress, 

pregnancy, 

menstruation, 

lactation, 

administration of steroids. 

Total leukocyte Count (TLC) Normal Range

Total leukocyte Count (TLC)

Normal Range (leucocytes/cumm)
Adults	New born	1-23 months
4000 – 10,500	9100 – 34,000	6000 – 14,000

Causes of lymphocytosis (> 4000/cumm in adults, > 7200/cumm adolescents, > 9000/cumm in children and infants)

Causes of lymphocytosis (> 4000/cumm in adults, > 7200/cumm adolescents, > 9000/cumm in children and infants)

Infection (Pertusis, infectious, lymphocytosis, infectious hepatitis, cytomegalovirus (CMV) infections, mumps, rubella, varicella, toxoplasmosis, chronic tuberculosis), 

Others like thyrotoxicosis, 

Addison's disease,

neutropenia with relative lymphocytosis, 

lymphatic leukemia, 

Crohn's disease, 

ulcerative colitis and 

infancy (normal count 40- 60 %) called relative lymphocytosis.