Finding the right tests…
Emergency services available 24 x 7
Emergency services available 24 x 7
Finding the right tests…
Haematology
TLC, or total leucocyte count, measures how many white blood cells are in a sample of your blood, without breaking that number down by cell type. White blood cells are your immune system's main defenders, so this count is a fast, direct read on whether your body is mounting an immune response right now. It's reported as part of a complete blood count, but a doctor may order it by itself when the specific question is just the trend of this one number, for example while tracking recovery from an infection or watching for a drop in white cells during chemotherapy, without needing the full panel each time.
The report gives a single number: white blood cells per microlitre of blood. A count above the expected range, called leukocytosis, often reflects an infection, inflammation, or stress response, though it can also come from smoking, certain medicines, or blood cancers. A count below the expected range, called leukopenia, can point toward bone marrow suppression, certain infections, autoimmune conditions, or medication effects. Because TLC doesn't distinguish between the different types of white cells, a differential count is added when your doctor needs to know which specific cell type is driving the change.
White blood cells are produced in bone marrow and circulate through your blood and tissues as your immune system's front line against infection. Total leucocyte count adds up every type of white cell into one number, giving a quick overall picture without the detail of which specific cell type is elevated or reduced.
When a doctor already has a working diagnosis and just wants to follow this one value over time, ordering TLC alone is faster and cheaper than repeating a full blood count. This comes up often during infection recovery, when a falling count toward normal is reassuring, and during chemotherapy, when a dropping count can mean a higher infection risk that needs monitoring.
A high or low TLC tells your doctor that something is affecting your white cell population, but not which of the several white cell types is responsible, since neutrophils, lymphocytes, eosinophils, monocytes, and basophils all get counted together into this one figure. When the specific type matters, for instance to tell a bacterial infection from a viral one or an allergic reaction, a differential count is ordered alongside or instead of a standalone TLC.
MedlinePlus lists a typical adult range of about 4,500 to 11,000 white blood cells per microlitre. Ranges vary by lab, so check the range printed on your own report.
It's called leukocytosis and often reflects infection, inflammation, or physical stress, though smoking, some medicines, and blood cancers can raise it too. Your doctor interprets it alongside your symptoms.
It's called leukopenia. It can point toward bone marrow suppression, certain infections, autoimmune conditions, or medication side effects, including some chemotherapy drugs.
No. TLC gives one total number for all white blood cells combined. A differential count breaks that total down into the different white cell types, which is a separate, more detailed test.
This page is general information about the test, not medical advice. Your own report's reference ranges apply — please discuss your results with your doctor.
Sometimes the specific goal is tracking one value over time, such as recovery from infection or a chemotherapy-related drop. A standalone TLC answers that without repeating the full blood count each visit.
No. This TLC measures white blood cells in your blood. TLC Fluid measures white cells in a body fluid sample, such as cerebrospinal or joint fluid, which reflects a very different kind of problem.