Understand CBC markers in your lab result

Hemoglobin is the protein in red blood cells that carries oxygen from the lungs to every tissue and returns carbon dioxide back for exhalation.

The white blood cell count measures the total number of immune cells circulating in the blood. These cells defend the body against infections, allergens, and foreign substances.

The red blood cell count measures how many red blood cells are present per litre of blood. Red blood cells contain hemoglobin and are responsible for oxygen transport throughout the body.

Hematocrit measures the proportion of blood volume made up by red blood cells, expressed as a percentage.

MCV is the average size of your red blood cells. It is one of the most useful red-cell indices for narrowing down the type of anemia, and it is always read alongside hemoglobin, RBC, RDW, ferritin, vitamin B12 and folate rather than on its own.

MCH is the average amount of hemoglobin contained in a single red blood cell, measured in picograms.

MCHC measures the concentration of hemoglobin within red blood cells — essentially how densely packed with hemoglobin each cell is.

RDW measures the variation in size among red blood cells. A high RDW means cells vary considerably in size; a normal RDW means they are fairly uniform.

Platelets are tiny blood cells that help the blood clot when there is a cut or injury, preventing excessive bleeding.

Neutrophils are the most abundant white blood cell and the immune system's first responders, engulfing and destroying bacteria and fungi.

Lymphocytes are white blood cells that form the core of the adaptive immune system, producing antibodies (B cells) and directly targeting infected or cancerous cells (T cells).

Monocytes are large white blood cells that engulf debris, pathogens, and dead cells. They also mature into macrophages in tissues, playing a key role in chronic inflammation.

Eosinophils are white blood cells that play a role in allergic reactions and defending against parasitic infections.

Basophils are the smallest subset of the white blood cell differential — typically less than 1% of circulating WBCs. They release histamine and other mediators and are most informative when read together with the total WBC count and the rest of the differential rather than on their own.

Reticulocytes are immature red blood cells freshly released from the bone marrow. Their count reflects how actively the bone marrow is producing red blood cells.