Total Leukocyte Count (TLC) in Dehradun

What is a Total Leukocyte Count (TLC)?

The Total Leukocyte Count is a headcount of the white blood cells patrolling a fixed volume of your blood. White cells are the immune system's workforce, and their total number rises when the body mounts a response and falls when production is suppressed or consumption outpaces supply. A raised count, leukocytosis, most often means bacterial infection, but it also accompanies tissue injury, burns, physical stress, steroid treatment, smoking and, in the marked and persistent form, blood disorders. A low count, leukopenia, is typically seen in viral illnesses including dengue, in typhoid, with certain medicines, and where the bone marrow is not producing normally. The important limitation is that TLC is a single summary number: it tells you the immune system is busy or subdued, but not which of the five white-cell types is responsible or why. That is what the Differential Leukocyte Count adds, which is why the two are always reported together inside a Complete Blood Count and interpreted as a pair rather than separately.

Why take this test?

A TLC is advised for fever of any unclear cause, for suspected infection, for unexplained fatigue or recurrent illness, and before surgery as part of routine pre-operative screening. In Dehradun through the monsoon it carries particular weight: dengue characteristically lowers both white cells and platelets, whereas a bacterial infection typically raises the white count, so the direction of change is an early clue to what kind of fever a patient has. It is also used to follow a known infection's response to treatment, and to monitor patients on chemotherapy, anti-thyroid drugs or other medicines that can suppress the bone marrow, where a falling count needs prompt attention. It is essentially never worth ordering on its own, because a Complete Blood Count includes it along with the differential, haemoglobin and platelets for very little more.

• Fever where the cause is not yet clear
• Suspected bacterial or viral infection
• Monsoon fever in Dehradun, where dengue lowers the count
• Unexplained fatigue or recurrent illness
• Routine pre-operative screening
• Monitoring chemotherapy or other marrow-suppressing medicines

Normal reference ranges

Ranges are indicative for adults. Your report carries the lab-specific reference range and is reviewed by a LabONE pathologist; always interpret results with your doctor.

FAQs: Total Leukocyte Count (TLC) in Dehradun