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Keep track of your blood health – know your blood cell counts

You are healthy, feel well and have no symptoms. However, on routine health examination, one of the parameters of your blood cell counts test, for instance, Hemoglobin is just on margin. You are recommended to take supplements by your physician. Likewise, blood cell counts are essential in case you have any symptoms. Let us review how Complete Blood Count (CBC) with differential test keeps track of your health, both in health and disease.


Uses of Complete Blood Count (CBC) With Differential test

Complete Blood Count (CBC) With Differential test provides information on several parameters which includes counts of the cells present in a sample of your blood, the number of cell types and the physical characteristics of the cells. The CBC with differential test is used for the:

  • Evaluation of White Blood Cells (WBCs): WBC count including a WBC differential which consists of determination of the count of types of WBCs namely neutrophils, eosinophils, basophils, monocytes and lymphocytes.
  • Evaluation of Red Blood Cells (RBCs): RBC count, Hemoglobin (Hb), Hematocrit (Hct) and RBC indices which include Mean Corpuscular Volume (MCV), Mean Corpuscular Hemoglobin (MCH), Mean Corpuscular Hemoglobin Concentration (MCHC), Red Cell Distribution Width (RDW); may or may not include reticulocyte count.
  • Evaluation of platelets: Platelet count; may or may not include Mean Platelet Volume (MPV) and Platelet Distribution Width (PDW).

Indications of Complete Blood Count (CBC) with differential test

Your physician will order Complete Blood Count (CBC) with differential test due to the following reasons:

  • To review your overall health: CBC with differential test is recommended by your physician as a component of a routine medical examination to monitor your general health and to screen for different disorders such as anemia or leukemia.
  • To diagnose a medical condition: In case you have weakness, fatigue, fever, inflammation, bruising or bleeding, your physician will order CBC with differential test for diagnosing the cause of these signs and symptoms.
  • To monitor a medical condition: In case you have been diagnosed with a blood disorder that affects blood cell counts, your physician may use complete blood counts to monitor your condition.
  • To monitor medical treatment: In case you are taking medications that may affect blood cell counts, CBC with differential test is indicated for monitoring your treatment.

Conditions with altered Complete Blood Count (CBC) with differential test

We will review some conditions when your blood counts are not within acceptable range. There can be alteration in one parameter, for instance either RBC indices or WBC levels or platelet counts or all the three parameters may be altered.


There is a relation between the results of your Red Blood Cell count, Hemoglobin and Hematocrit since they each measure aspects of your RBCs. You have anemia in case the values of either of these indices is lower than normal. Anemia causes fatigue, weakness, pallor and dizziness. Anemia has many causes, including low levels of certain vitamins or iron, blood loss or an underlying condition.

Red blood cell indices are used to differentiate between Iron deficiency anemia and Thalassemia (both are types of microcytic anemia (anemia with small sized RBCs)). Studies have shown that there is considerable overlapping between the red cell indices such as MCV, MCH, MCHC between Iron deficiency anemia and Thalassemia. However, RDW is the most reliable indicator to differentiate between them, which further impacts the management of the two conditions. Thus, CBC with differential test plays a beneficial role in this regard.

Infection or Inflammation

In case you have an infection or inflammation, your White Blood Cell count is higher than normal. The differential WBC count will show increase in the number of your neutrophils. The results of your differential WBC count in conjunction with your symptoms will aid your physician to proceed with further testing to establish the diagnosis.

Neutrophilia can occur from acute infections caused by bacteria such as Staphylococci causing furuncles, Streptococci causing tonsillitis and otitis media, Pneumococci causing pneumonia, Meningococci causing meningitis, Gonococci causing gonorrhea, Escherichia coli involved in gastrointestinal tract infections and Pseudomonas aeruginosa causing abscesses. Certain fungi such as Candida albicans, viruses such as Rabies, Poliomyelitis, Herpes zoster, Smallpox, Varicella and parasites such as Liver fluke also cause neutrophilia. Infections such as Typhoid fever, Parathyroid fever, Mumps, Measles and Tuberculosis usually are not associated with neutrophilia. In non-infectious inflammatory conditions, such as burns, acute Asthma, Myocardial infarction, acute attacks of Gout, acute Glomerulonephritis, Rheumatic fever, collagen-vascular diseases, hypersensitivity reactions and even cigarette smoking, neutrophilia can occur. Various other conditions will raise the blood levels of other types of white blood cells, thereby proving the importance of differential WBC count.


In case, you have a tendency to bleed or bruise easily, you may have thrombocytopenia or platelet count lower than normal range. If your platelet count is outside the normal range, you will likely need additional tests such as blood smear and bone marrow biopsy to diagnose the cause.

Thrombocytopenia can be inherited or acquired. "Inherited" means your parents transmitted the gene for the condition to you. "Acquired" means you were not born with the condition but got it during your lifetime. A low platelet count occurs when either your body's bone marrow doesn't make enough platelets, for instance in cancers, exposure to toxic chemicals, medicines, alcohol and viruses; your bone marrow makes enough platelets but the body destroys them or uses them up in cases of autoimmune diseases such as immune thrombocytopenic purpura (ITP), exposure to medications, infections or surgery; or your spleen hold on too many platelets without releasing them into circulation in conditions such as cancer or liver diseases. Whatsoever may be the cause, CBC with differential test will reveal the altered platelet counts.

Thus, CBC with differential test assists you in tracking your blood health. Your physician will decide on your further management based on the outcome of your blood count test and your clinical presentation.