Understanding Your Complete Blood Count (CBC) Results
A Complete Blood Count measures three cell lines your bone marrow produces: red blood cells (which carry oxygen via haemoglobin), white blood cells (your immune system's frontline), and platelets (tiny fragments critical for clotting). The CBC also reports haematocrit — the percentage of blood volume made up of red cells — and MCV (mean corpuscular volume), which classifies the type of anaemia when present. It is one of the most ordered tests globally and the starting point for investigating fatigue, infection, bleeding, and many chronic diseases.
Normal Reference Ranges
>>>| Parameter | Normal Range | Unit | Note |
|---|---|---|---|
| White Blood Cells (WBC) | 4,000–11,000 | cells/µL | Total immune cells |
| Red Blood Cells (RBC) — Men | 4.5–5.5 | million/µL | — |
| Red Blood Cells (RBC) — Women | 4.0–5.0 | million/µL | — |
| Haemoglobin — Men | 13.5–17.5 | g/dL | — |
| Haemoglobin — Women | 12.0–16.0 | g/dL | — |
| Haematocrit — Men | 41–53 | % | — |
| Haematocrit — Women | 36–46 | % | — |
| MCV (Mean Corpuscular Volume) | 80–100 | fL | Size of red cells |
| Platelets | 150,000–400,000 | cells/µL | — |
Reference ranges may vary slightly between laboratories. Always compare your result to the range printed on your specific lab report.
What High Complete Blood Count (CBC) Results Mean
High WBC (leukocytosis, above 11,000/µL) most commonly signals active infection — bacterial infections typically cause elevated neutrophils, while viral infections raise lymphocytes. Persistent or markedly elevated WBC (above 30,000) with abnormal cell morphology raises concern for leukaemia and requires urgent haematology review. High platelets (thrombocytosis, above 400,000) can follow infection, surgery, or iron deficiency, and is usually reactive and benign; values above 1,000,000 require investigation. Elevated haemoglobin (polycythaemia) may be due to dehydration, chronic lung disease, or, rarely, a bone marrow condition.
What Low Complete Blood Count (CBC) Results Mean
Low haemoglobin (anaemia) is the most clinically significant CBC finding. In the UAE, iron deficiency is the most common cause — particularly in South Asian and Filipino women of reproductive age, with studies reporting rates above 30% in certain demographics. Low MCV (below 80 fL, microcytic anaemia) points to iron deficiency or thalassaemia trait, both common in UAE populations. High MCV (above 100 fL, macrocytic anaemia) suggests B12 or folate deficiency. Low WBC (below 4,000) may indicate viral infection, certain medications, or bone marrow suppression. Low platelets (below 150,000, thrombocytopenia) are seen with dengue fever — highly relevant in Dubai and Abu Dhabi given the endemic risk — viral infections, or immune thrombocytopenia.
When to See a Doctor
See a doctor promptly if: haemoglobin drops below 8 g/dL (severe anaemia causing breathlessness or chest pain); WBC exceeds 30,000/µL or falls below 2,000/µL; platelets fall below 50,000/µL (bleeding risk) or rise above 1,000,000/µL; or if the lab report flags abnormal cell morphology (blasts, hypersegmented neutrophils, or schistocytes). Dengue-related thrombocytopenia below 20,000/µL is a medical emergency. Any combination of low WBC, low haemoglobin, and low platelets (pancytopenia) requires urgent evaluation.
UAE Health Context
Thalassaemia trait — a genetic condition reducing haemoglobin production — is common in UAE nationals and populations from the Indian subcontinent, Southeast Asia, and the Mediterranean. It produces a picture similar to iron deficiency on a CBC (low MCV, low haemoglobin) but iron stores are normal or elevated. The UAE mandates pre-marital thalassaemia screening precisely because of this prevalence. CBC is included in UAE visa medicals for domestic workers and certain job categories. Dengue fever, which causes rapid platelet drops, has seasonal outbreaks in the UAE — a falling platelet count in a febrile patient warrants dengue serology.
What to Do Next
If your CBC is abnormal, your doctor will typically order follow-up tests based on the specific finding: iron studies and ferritin for suspected iron deficiency; a peripheral blood smear to examine cell morphology; vitamin B12 and folate for macrocytic anaemia; haemoglobin electrophoresis if thalassaemia is suspected; or dengue NS1 antigen / antibody if platelets are low with fever. Do not start iron supplementation without confirmation of iron deficiency — in thalassaemia trait, iron supplements are unnecessary and can cause harm.
Related Tests Often Ordered Together
>>>Frequently Asked Questions
What is a normal Complete Blood Count (CBC) level?
Normal Complete Blood Count (CBC) ranges vary by parameter. White Blood Cells (WBC): 4,000–11,000 cells/µL; Red Blood Cells (RBC) — Men: 4.5–5.5 million/µL; Red Blood Cells (RBC) — Women: 4.0–5.0 million/µL; Haemoglobin — Men: 13.5–17.5 g/dL; Haemoglobin — Women: 12.0–16.0 g/dL; Haematocrit — Men: 41–53 %; Haematocrit — Women: 36–46 %; MCV (Mean Corpuscular Volume): 80–100 fL; Platelets: 150,000–400,000 cells/µL. Always compare your results against the reference range on your specific lab report, as ranges can vary slightly between laboratories.
What causes high Complete Blood Count (CBC)?
High WBC (leukocytosis, above 11,000/µL) most commonly signals active infection — bacterial infections typically cause elevated neutrophils, while viral infections raise lymphocytes. Persistent or markedly elevated WBC (above 30,000) with abnormal cell morphology raises concern for leukaemia and requires urgent haematology review. High platelets (thrombocytosis, above 400,000) can follow infection, surgery, or iron deficiency, and is usually reactive and benign; values above 1,000,000 require investigation. Elevated haemoglobin (polycythaemia) may be due to dehydration, chronic lung disease, or, rarely, a bone marrow condition.
Do I need to fast before a Complete Blood Count (CBC) test?
No, fasting is not required for this test. It can be done at any time of day without dietary restrictions.
How often should I get a Complete Blood Count (CBC) test?
Annually as part of routine health screening; every 3–6 months if managing a blood disorder or chronic disease.
Medical Disclaimer: The information on this page is provided for general educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Reference ranges are general guidelines — your doctor will interpret your results in the context of your full clinical picture, symptoms, and medical history. If you have concerns about your test results, always consult a licensed healthcare professional. Do not delay seeking medical advice or disregard professional medical guidance because of information on this page.