Understanding Blood Test Results: WBC, Hemoglobin, Platelets & More

Posted on Nov 23, 2024 in Biology

WBC Count (WCC)

Normal value: 3,500 – 11,000/mL.
White blood cells, or leukocytes, are defense cells circulating in the bloodstream. Types include neutrophils, lymphocytes, monocytes, and eosinophils. The total value is the sum of all types; an increase or decrease in one type affects the overall count.

  • Neutrophils: Normal value: 2,000 – 7,500/mL. The most numerous, they attack foreign substances (bacteria, external agents). Their numbers increase during infection or inflammation. ‘Immature’ neutrophils, called ‘bands’ or ‘stabs,’ appear during infections and are indicated as a percentage, normally zero.
  • Lymphocytes: Normal value: 1,000 – 4,500/mL. Increase in viral or parasitic infections, some tumors, or leukemias.
  • Monocytes: Normal value: 200 – 800/mL. Elevated in viral or parasitic infections, some tumors, or leukemias.
  • Eosinophils: Increase in parasitic diseases, allergies, and asthma.

WBC Decrease

Hemoglobin (HGB)

Normal value: 12.5 – 17 g/dL.
Hemoglobin is a protein in red blood cells that carries oxygen. Its amount is usually proportional to the red blood cell count. A higher-than-normal value indicates an increase in red blood cells, as does a lower-than-normal value. Red blood cells link.

Thalassemia is an exception: individuals have many small red blood cells with relatively little hemoglobin.

Corpuscular Volume (MCV)

Normal value: 78 – 100 fL.
Indicates the size of red blood cells.

  • High MCV (large red blood cells): Occurs in vitamin B12 or folic acid deficiency, liver diseases, or high alcohol consumption. Some individuals have slightly larger red cells without disease.
  • Low MCV (small red blood cells): Occurs in thalassemia (altered hemoglobin, reducing erythrocyte size) and iron deficiency.

Mean Corpuscular Hemoglobin (MCH)

Normal value: 27 – 32 pg.
Indicates the amount of hemoglobin in each red blood cell, essentially the ‘redness’ of the cells. Increased in vitamin B12 or folic acid deficiency; decreased in iron deficiency or thalassemia.

Platelets

Normal value: 130,000 – 450,000/mL.
Platelets are blood cells responsible for hemostasis (stopping bleeding by closing wounds and forming clots).

Platelet Increase

Platelets may increase temporarily or chronically due to illness or acute hemorrhage. Some blood disorders cause consistently high platelet counts (two to three times normal), sometimes requiring chemotherapy to prevent blood clots.

Platelet Decrease

  • Serious infections can reduce cell production in bone marrow, causing anemia, low platelets, and low leukocytes.
  • Some individuals have antibodies that destroy their platelets (idiopathic thrombocytopenic purpura), more common in young women. Spontaneous bleeding risk increases if counts fall below 10,000/mL.
  • An overactive spleen (an organ that helps fight infections) can enlarge due to chronic liver disease, etc., and remove too many blood cells.

Sedimentation Rate (ESR)

Normal value: Below 20 mm/h.
ESR is related to the tendency of red blood cells to clump together and the amount of protein in plasma.

ESR Increase

  • Infections
  • Chronic inflammatory diseases (lupus, rheumatoid arthritis, polymyalgia rheumatica, etc.)
  • Anemia

ESR is a non-specific test; it doesn’t pinpoint the site of infection or inflammation but indicates a condition needing diagnosis. It’s also useful for monitoring treatment effectiveness, as successful treatment reduces ESR.