Full Blood Count (FBC): Complete Guide to Results & What They Mean
FULL BLOOD COUNT (FBC)
Complete Blood Count (CBC) Test
A Detailed Plain-Language Explanation of Every Result — Written for Nigerian Patients
Published by: Omokos Diagnostics and Clinical Services Ltd
Reviewed by: Scientist Shuaibu Omoko | Founder, Omokos Diagnostics
Published: 2026 | Benin City, Edo State, Nigeria
Medical Disclaimer: This article is for educational purposes only. It does not constitute medical advice. Always consult a qualified healthcare provider about your specific results.
You have just received your Full Blood Count (FBC) result. The sheet in your hand contains a long list of numbers — haemoglobin, PCV, WBC, neutrophils, lymphocytes, eosinophils, platelets, MCV, MCH, MCHC — and next to some of these numbers there are little arrows pointing up or down, or the word HIGH or LOW.
What does it all mean? What is your body telling you through these numbers? And what should you do if something is abnormal?
This comprehensive guide answers every one of those questions. Written specifically for Nigerian patients by the team at Omokos Diagnostics and Clinical Services Ltd in Benin City, this article takes you through every single parameter in a standard Full Blood Count result — explaining it in plain language, giving you the normal ranges, and telling you exactly what low and high values may mean for your health.
The Full Blood Count is the most commonly requested laboratory test in medicine worldwide — and for good reason. It provides a window into three of the most critical systems in your body: your red blood cell system, your immune system, and your blood clotting system — all from a single blood sample.
What This Guide Covers
- What Is a Full Blood Count and Why Is It Done?
- How Is the Blood Sample Collected?
- Part 1: Red Blood Cell Parameters — Haemoglobin, PCV, RBC Count, MCV, MCH, MCHC, RDW
- Part 2: White Blood Cell Parameters — Total WBC, Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils
- Part 3: Platelet Parameters — Platelet Count, MPV, PDW
- Complete FBC Reference Table — All Parameters at a Glance
- Understanding Your FBC in Context — What Different Patterns Mean
- FBC and Common Nigerian Health Conditions
- When Is the FBC Repeated?
- Frequently Asked Questions
- References
1. What Is a Full Blood Count and Why Is It Done?
The Full Blood Count (FBC) — also called Complete Blood Count (CBC) — is a comprehensive laboratory test that measures and analyses the three main types of cells found in your blood:
- Red Blood Cells (RBCs) — also called erythrocytes — carry oxygen from the lungs to every cell in your body and return carbon dioxide back to the lungs
- White Blood Cells (WBCs) — also called leucocytes — form the backbone of your immune system, fighting infections, parasites, bacteria, viruses, and other threats
- Platelets — also called thrombocytes — are tiny cell fragments that are essential for blood clotting and stopping bleeding when a vessel is damaged
Beyond counting these cells, the FBC also measures important characteristics of each cell type — their size, shape, haemoglobin content, and distribution — providing rich diagnostic information from a single blood sample.
Doctors request a Full Blood Count for many reasons:
| Reason for FBC Request | What the Doctor Is Looking For |
| Symptoms of tiredness, weakness, or pallor | Anaemia — low haemoglobin or red blood cell count |
| Fever, infection, or inflammation | Elevated white blood cells indicating immune response |
| Unexplained weight loss or night sweats | Blood cancers such as leukaemia or lymphoma |
| Abnormal bleeding or bruising | Low platelet count or clotting disorder |
| Routine health screening or annual check-up | Baseline blood health assessment |
| Before surgery or hospital admission | Pre-operative assessment of blood health |
| Monitoring chronic conditions (malaria, sickle cell, HIV) | Ongoing haematological surveillance |
| Monitoring response to treatment | Anaemia treatment, chemotherapy, or antiretroviral therapy |
| Pregnancy — antenatal care | Detecting anaemia, infection, or platelet disorders |
| Suspected malaria or typhoid | Blood cell changes associated with these infections |
2. How Is the Blood Sample Collected?
The Full Blood Count requires a venous blood sample — a small amount of blood drawn from a vein, usually in the arm. Here is what to expect:
- A tourniquet is applied to your upper arm to make the vein more visible
- The skin is cleaned with an antiseptic swab
- A needle is inserted into the vein and blood is drawn into a special tube — the EDTA (purple or lavender top) tube — which contains an anticoagulant that prevents the blood from clotting
- The needle is removed, pressure is applied to the site, and a cotton ball or plaster is placed over the puncture
- The process takes less than 2 minutes and causes only brief, mild discomfort
For a standard Full Blood Count, fasting is not required. The test can be done at any time of day. However, if your doctor has requested additional tests alongside the FBC — such as a fasting blood sugar or lipid profile — you may need to fast for 8 to 12 hours.
At Omokos Diagnostics and Clinical Services Ltd in Benin City, our trained phlebotomists perform blood collection with precision and patient comfort in mind. Walk in or book your FBC appointment at www.omokosdiagnostics.com.ng
3. Part 1: Red Blood Cell Parameters
Red blood cells are the most numerous cells in the blood. Their primary job is to carry haemoglobin — a protein that binds oxygen in the lungs and releases it to tissues throughout the body. The FBC measures several aspects of red blood cell health.
3.1 Haemoglobin (Hb)
Haemoglobin is the iron-containing protein in red blood cells that carries oxygen. It is the single most important parameter in the FBC for assessing anaemia.
| Group | Normal Haemoglobin Range | Anaemia Classification |
| Adult Men | 13.5 — 17.5 g/dL | Below 13.0 g/dL = anaemia |
| Adult Women (non-pregnant) | 12.0 — 15.5 g/dL | Below 12.0 g/dL = anaemia |
| Pregnant Women | Above 11.0 g/dL | Below 11.0 g/dL = anaemia in pregnancy |
| Children (6 months — 5 years) | 11.0 — 14.0 g/dL | Below 11.0 g/dL = anaemia |
| Children (5 — 12 years) | 11.5 — 15.5 g/dL | Below 11.5 g/dL = anaemia |
Severity of anaemia by haemoglobin level:
| Haemoglobin Level | Severity of Anaemia | Typical Symptoms |
| 10.0 — 11.9 g/dL (women) / 10.0 — 12.9 g/dL (men) | Mild anaemia | Mild fatigue, occasional breathlessness on exertion |
| 8.0 — 9.9 g/dL | Moderate anaemia | Fatigue, pallor, breathlessness, dizziness, palpitations |
| Below 8.0 g/dL | Severe anaemia | Extreme weakness, severe breathlessness, chest pain, rapid pulse |
| Below 6.0 g/dL | Very severe anaemia | Life-threatening — requires urgent blood transfusion |
Common causes of LOW haemoglobin (anaemia) in Nigeria:
- Iron deficiency — the most common cause, often from poor diet, blood loss, or heavy menstruation
- Malaria — destroys red blood cells, common cause of anaemia especially in children and pregnant women
- Sickle cell disease — haemolytic anaemia from abnormal red blood cells breaking down prematurely
- Vitamin B12 and folate deficiency — megaloblastic anaemia
- Chronic kidney disease — reduced erythropoietin production
- HIV infection and antiretroviral therapy side effects
- Hookworm and other intestinal parasites — blood loss in the gut
- Pregnancy — physiological haemodilution plus increased iron demand
Causes of HIGH haemoglobin (polycythaemia):
- Dehydration — the most common cause — blood is concentrated
- Chronic lung disease — body produces extra red cells to compensate for low oxygen
- Living at high altitude — physiological response
- Polycythaemia vera — rare bone marrow condition producing too many red cells
3.2 Packed Cell Volume (PCV) / Haematocrit (HCT)
The PCV (also called haematocrit) measures the proportion of your blood volume that is made up of red blood cells, expressed as a percentage. It closely mirrors haemoglobin and is used to assess anaemia and polycythaemia.
| Group | Normal PCV Range | Below Normal (Anaemia) | Above Normal |
| Adult Men | 41 — 53% | Below 41% | Above 53% |
| Adult Women | 36 — 46% | Below 36% | Above 46% |
| Pregnant Women | Above 33% | Below 33% | Rare in pregnancy |
| Children | 33 — 43% | Below 33% | Above 43% |
PCV and haemoglobin carry essentially the same clinical information. A rough rule of thumb: PCV (%) is approximately three times the haemoglobin (g/dL). So a haemoglobin of 12 g/dL corresponds to approximately 36% PCV.
3.3 Red Blood Cell Count (RBC)
The RBC count measures the actual number of red blood cells per litre (or microlitre) of blood. It is used alongside haemoglobin and PCV to characterise the type of anaemia.
| Group | Normal RBC Range |
| Adult Men | 4.5 — 5.9 million cells/microlitre (x10^6/uL) |
| Adult Women | 4.0 — 5.2 million cells/microlitre (x10^6/uL) |
| Children | 3.8 — 5.2 million cells/microlitre (x10^6/uL) |
- Low RBC count alongside low haemoglobin confirms anaemia
- Low RBC with normal or high haemoglobin per cell (high MCH/MCHC) — macrocytic or vitamin deficiency anaemia
- High RBC count — polycythaemia, dehydration, or high altitude
3.4 Mean Corpuscular Volume (MCV) — The Size of Your Red Cells
MCV measures the average size (volume) of a single red blood cell. This is one of the most diagnostically useful parameters in the FBC because the size of red cells gives direct clues about the CAUSE of anaemia.
| MCV Value | Classification | What It Means | Common Causes in Nigeria |
| Below 80 fL | Microcytic (small cells) | Red cells are smaller than normal | Iron deficiency anaemia — most common cause; Thalassaemia; Anaemia of chronic disease (sometimes) |
| 80 — 100 fL | Normocytic (normal size) | Red cells are normal size | Acute blood loss; Haemolytic anaemia (malaria, sickle cell); Anaemia of chronic disease; Mixed deficiency |
| Above 100 fL | Macrocytic (large cells) | Red cells are larger than normal | Vitamin B12 deficiency; Folate deficiency; Alcohol-related liver disease; Hypothyroidism; Some medications |
The MCV is the key to identifying the TYPE of anaemia. A low MCV strongly suggests iron deficiency — by far the most common cause of anaemia in Nigeria. A high MCV suggests B12 or folate deficiency. A normal MCV with low haemoglobin suggests malaria, sickle cell disease, or chronic illness.
3.5 Mean Corpuscular Haemoglobin (MCH) — Haemoglobin Content Per Cell
MCH measures the average amount of haemoglobin contained in a single red blood cell. It is closely related to MCV and interpreted in a similar way.
| MCH Value | Classification | Meaning |
| Below 27 pg | Hypochromic (pale cells) | Low haemoglobin per cell — iron deficiency or thalassaemia |
| 27 — 33 pg | Normochromic (normal) | Normal haemoglobin content — normal or acute blood loss anaemia |
| Above 33 pg | Hyperchromic (rich cells) | High haemoglobin per cell — B12 or folate deficiency (macrocytic anaemia) |
3.6 Mean Corpuscular Haemoglobin Concentration (MCHC)
MCHC measures the concentration of haemoglobin in a given volume of red blood cells — essentially how packed with haemoglobin the cells are.
| MCHC Value | Classification | Common Cause |
| Below 32 g/dL | Hypochromic — low concentration | Iron deficiency anaemia |
| 32 — 36 g/dL | Normal | Healthy or normocytic anaemia |
| Above 36 g/dL | Hyperchromic — high concentration | Hereditary spherocytosis; severe dehydration |
3.7 Red Cell Distribution Width (RDW) — Variation in Cell Size
RDW measures the degree of variation in red blood cell size. Normally, red blood cells are fairly uniform in size. When there is more variation — some cells very small, some very large — the RDW rises. This is called anisocytosis.
| RDW Value | Interpretation | Clinical Significance |
| 11.5 — 14.5% | Normal variation | Red cells are of relatively uniform size |
| Above 14.5% | High RDW — increased anisocytosis | Mixed anaemia (e.g. iron deficiency plus B12 deficiency); Early iron deficiency; Thalassaemia; Haemolytic anaemia; Recent blood transfusion |
The RDW is particularly useful when combined with MCV:
| MCV + RDW Pattern | Most Likely Diagnosis |
| Low MCV + High RDW | Iron deficiency anaemia — the classic pattern |
| Low MCV + Normal RDW | Thalassaemia trait — cells small and uniform |
| Normal MCV + High RDW | Mixed deficiency (iron + B12/folate) or early iron/B12 deficiency |
| High MCV + High RDW | B12 or folate deficiency; Liver disease; Haemolytic anaemia |
| Normal MCV + Normal RDW | Normal or anaemia of chronic disease |
4. Part 2: White Blood Cell Parameters
White blood cells (leucocytes) are your body’s immune army. They identify and destroy bacteria, viruses, fungi, and parasites. Unlike red blood cells, which are all the same type, white blood cells come in five distinct types — each with a different role in your immune defence. The FBC measures both the total WBC count and the proportion of each type — called the differential count.
4.1 Total White Blood Cell Count (WBC)
| WBC Count | Classification | Possible Causes |
| Below 4,000 cells/uL | Leucopenia (low WBC) | Viral infections (HIV, typhoid, dengue), bone marrow suppression, autoimmune conditions, chemotherapy, severe sepsis |
| 4,000 — 11,000 cells/uL | Normal range | Healthy immune system |
| 11,000 — 30,000 cells/uL | Leucocytosis (high WBC) | Bacterial infection, inflammation, tissue injury, stress response, steroid use, leukaemia |
| Above 30,000 cells/uL | Extreme leucocytosis | Severe bacterial infection, leukaemia, or leukaemoid reaction |
A very high WBC count — especially above 50,000 cells/uL — may suggest leukaemia (blood cancer) and requires urgent haematology review. However, most elevations are caused by infection or inflammation and are not dangerous. Context and the differential count matter enormously.
4.2 Neutrophils — The First Responders to Bacterial Infection
Neutrophils are the most abundant white blood cell, making up 40 to 70 percent of all WBCs. They are the immune system’s first responders — rushing to the site of bacterial infection or tissue injury within minutes and engulfing (phagocytosing) and destroying bacteria.
| Neutrophil Result | Normal Range | Low (Neutropenia) | High (Neutrophilia) |
| Absolute count | 1,800 — 7,700 cells/uL | Below 1,800 — risk of serious bacterial infection | Above 7,700 — bacterial infection, inflammation, stress, steroids |
| Percentage of WBC | 40 — 70% | Below 40% of WBC | Above 70% of WBC |
- Neutrophilia (high neutrophils) — most commonly seen in bacterial infections, appendicitis, pneumonia, abscesses, severe tissue injury, and corticosteroid use
- Neutropenia (low neutrophils) — viral infections (HIV, dengue), typhoid fever, bone marrow suppression, chemotherapy, autoimmune conditions
- Bands (immature neutrophils) — the presence of immature neutrophils called bands or stab cells suggests a severe acute bacterial infection where the bone marrow is releasing immature cells — called a left shift
4.3 Lymphocytes — The Immune Memory Cells
Lymphocytes are the second most common white blood cells, making up 20 to 40 percent of all WBCs. They are responsible for specific immune responses — producing antibodies (B lymphocytes) and directly killing infected or cancerous cells (T lymphocytes).
| Lymphocyte Result | Normal Range | Low (Lymphopenia) | High (Lymphocytosis) |
| Absolute count | 1,000 — 4,800 cells/uL | Below 1,000 — immune deficiency | Above 4,800 — viral infection, chronic infection |
| Percentage of WBC | 20 — 40% | Below 20% | Above 40% |
- Lymphocytosis (high lymphocytes) — viral infections (Epstein-Barr virus, cytomegalovirus, hepatitis, whooping cough), typhoid fever, tuberculosis, chronic lymphocytic leukaemia
- Lymphopenia (low lymphocytes) — HIV infection (CD4 T cell depletion), corticosteroid use, severe sepsis, autoimmune conditions, bone marrow disorders
In Nigeria, a persistently low lymphocyte count — particularly below 1,000 cells/uL — should always prompt consideration of HIV testing. HIV selectively destroys a specific type of lymphocyte (CD4 T cells), leading to immunodeficiency.
4.4 Monocytes — The Clean-Up Crew
Monocytes are large white blood cells that make up 2 to 8 percent of all WBCs. They circulate in the blood for a short period before entering tissues and transforming into macrophages — large cells that engulf and digest bacteria, dead cells, and debris.
| Monocytes | Normal Range | Low | High (Monocytosis) |
| Percentage | 2 — 8% of WBC | Rarely significant alone | Tuberculosis, malaria, typhoid, inflammatory bowel disease, monocytic leukaemia, recovery from acute infection |
4.5 Eosinophils — The Parasite Fighters and Allergy Responders
Eosinophils make up 1 to 4 percent of all WBCs. In Nigeria, eosinophil count is particularly important because elevated eosinophils (eosinophilia) is one of the most common and clinically significant FBC findings.
| Eosinophil Count | Classification | Common Causes in Nigeria |
| Below 500 cells/uL (or below 4% of WBC) | Normal | Healthy immune system |
| 500 — 1,500 cells/uL | Mild eosinophilia | Early parasitic infection, mild allergic reaction, drug reaction |
| 1,500 — 5,000 cells/uL | Moderate eosinophilia | Active parasitic infection (hookworm, ascaris, filariae, schistosoma), asthma, eczema, drug allergy |
| Above 5,000 cells/uL | Severe eosinophilia (hypereosinophilia) | Heavy parasitic infestation, hypereosinophilic syndrome, eosinophilic leukaemia |
The most important causes of eosinophilia in Nigeria:
- Intestinal parasites — hookworm, roundworm (Ascaris), threadworm, tapeworm — very common in Nigeria
- Tissue parasites — filariasis, schistosomiasis, toxocariasis
- Allergic conditions — asthma, allergic rhinitis, atopic eczema
- Drug reactions — reactions to antibiotics, NSAIDs, and other medications
Elevated eosinophils in a Nigerian patient should immediately prompt consideration of parasitic infection. This is particularly important in children and rural populations. A stool examination and specific parasite tests may be needed to identify the causative organism.
4.6 Basophils — The Rarest White Blood Cell
Basophils are the least common white blood cells, normally comprising only 0 to 1 percent of all WBCs. They play a role in allergic and inflammatory responses.
- Normal basophil percentage: 0 — 1% of total WBC
- Basophilia (high basophils) — chronic myeloid leukaemia (a key feature), allergic reactions, hypothyroidism
- Basopenia (low basophils) — rarely clinically significant on its own
5. Part 3: Platelet Parameters
Platelets are small, disc-shaped cell fragments produced in the bone marrow. When a blood vessel is damaged, platelets rush to the site, stick together, and form a plug that stops bleeding. They are essential for blood clotting.
5.1 Platelet Count
| Platelet Count | Classification | Clinical Significance |
| Below 50,000 /uL | Severe thrombocytopenia | High risk of spontaneous serious bleeding — urgent medical evaluation |
| 50,000 — 100,000 /uL | Moderate thrombocytopenia | Significant bleeding risk — medical evaluation required |
| 100,000 — 150,000 /uL | Mild thrombocytopenia | Mildly increased bleeding risk — investigate underlying cause |
| 150,000 — 400,000 /uL | Normal range | Normal platelet count — adequate clotting capacity |
| 400,000 — 600,000 /uL | Mild thrombocytosis | May be reactive (infection, inflammation, iron deficiency) or essential |
| Above 600,000 /uL | Significant thrombocytosis | Risk of clotting — investigate for myeloproliferative disorder |
Common causes of LOW platelets (thrombocytopenia) in Nigeria:
- Malaria — one of the most common causes in Nigeria. Malaria parasites damage platelets directly and activate their consumption. Platelet count below 100,000/uL in a febrile patient should raise immediate suspicion for malaria.
- Dengue fever — platelet destruction is a hallmark of dengue
- Typhoid fever — Salmonella infection causes platelet suppression
- HIV infection — immune-mediated platelet destruction
- Viral hepatitis B and C — liver disease impairs platelet production
- Severe sepsis — platelets consumed in clotting throughout the body
- Leukaemia and bone marrow disorders — reduced platelet production
- Immune thrombocytopenic purpura (ITP) — immune attack on platelets
A platelet count below 100,000/uL in any Nigerian patient with fever should be treated as malaria until proven otherwise — and a malaria test should be performed immediately alongside treatment. This can be life-saving.
5.2 Mean Platelet Volume (MPV)
MPV measures the average size of platelets. Younger, more active platelets tend to be larger.
| MPV Value | Interpretation |
| 7.5 — 12.5 fL (normal) | Normal platelet size and activity |
| Above 12.5 fL (high MPV) | Large platelets — bone marrow is producing more platelets actively (compensating for destruction) — seen in ITP, recovery from thrombocytopenia, cardiovascular risk |
| Below 7.5 fL (low MPV) | Small platelets — bone marrow platelet production is suppressed — seen in aplastic anaemia, chemotherapy |
5.3 Platelet Distribution Width (PDW)
PDW measures the variation in platelet size. A high PDW means there is a wide variation — some very large platelets and some very small ones. This suggests active platelet production or destruction. PDW is less commonly reported but adds useful context to the platelet count and MPV.
6. Complete FBC Reference Table — All Parameters at a Glance
Use this table as your complete quick-reference guide for understanding every parameter on your FBC result sheet:
| Parameter | Abbreviation | Normal Range (Adults) | Low Means | High Means |
| Haemoglobin | Hb | Men: 13.5–17.5 g/dL Women: 12.0–15.5 g/dL | Anaemia | Polycythaemia, dehydration |
| Packed Cell Volume | PCV / HCT | Men: 41–53% Women: 36–46% | Anaemia | Polycythaemia, dehydration |
| Red Blood Cell Count | RBC | Men: 4.5–5.9 M/uL Women: 4.0–5.2 M/uL | Anaemia | Polycythaemia |
| Mean Corpuscular Volume | MCV | 80–100 fL | Iron deficiency, thalassaemia | B12/folate deficiency, liver disease |
| Mean Corpuscular Haemoglobin | MCH | 27–33 pg | Iron deficiency | B12/folate deficiency |
| MCHC | MCHC | 32–36 g/dL | Iron deficiency | Spherocytosis, dehydration |
| Red Cell Distribution Width | RDW | 11.5–14.5% | Rarely significant | Iron def., mixed anaemia, haemolysis |
| Total White Blood Cell | WBC | 4,000–11,000 /uL | Viral infection, HIV, bone marrow | Bacterial infection, leukaemia |
| Neutrophils | NEUT | 40–70% / 1,800–7,700 /uL | Viral infection, typhoid, chemotherapy | Bacterial infection, inflammation |
| Lymphocytes | LYMPH | 20–40% / 1,000–4,800 /uL | HIV, steroids, severe sepsis | Viral infection, CLL, typhoid |
| Monocytes | MONO | 2–8% of WBC | Rarely significant | TB, malaria, typhoid, leukaemia |
| Eosinophils | EOS | 1–4% of WBC | Rarely significant | Parasites, allergy, asthma |
| Basophils | BASO | 0–1% of WBC | Rarely significant | CML, allergy, hypothyroidism |
| Platelet Count | PLT | 150,000–400,000 /uL | Malaria, dengue, ITP, leukaemia | Infection, iron def., myeloproliferative |
| Mean Platelet Volume | MPV | 7.5–12.5 fL | Bone marrow suppression | Active platelet production, cardiovascular risk |
7. Understanding Your FBC in Context — What Different Patterns Mean
Experienced clinicians do not look at individual FBC parameters in isolation. They look at patterns — combinations of abnormal values that together point to a specific diagnosis. Here are the most common and important FBC patterns:
| FBC Pattern | What It Suggests |
| Low Hb + Low MCV + Low MCH + High RDW | Classic iron deficiency anaemia — most common anaemia in Nigeria |
| Low Hb + Low MCV + Normal RDW + Normal MCH | Thalassaemia trait — cells are small but uniform, iron stores normal |
| Low Hb + High MCV + High MCH + High RDW | Megaloblastic anaemia — B12 or folate deficiency |
| Low Hb + Normal MCV + Normal RDW + Normal MCH | Anaemia of chronic disease or acute blood loss — investigate underlying cause |
| Low Hb + Normal MCV + Low RBC count with abnormal cell shapes on film | Haemolytic anaemia — malaria, sickle cell, or autoimmune — red cells being destroyed |
| Very High WBC + Many immature cells (blasts) | Possible leukaemia — urgent haematology referral needed |
| Low WBC + Low platelets + Low Hb (pancytopenia) | Bone marrow failure, aplastic anaemia, or advanced leukaemia |
| High WBC + High neutrophils + Fever | Active bacterial infection — identify source and treat |
| Low platelets + Fever + Malaria-prone area | Malaria until proven otherwise — test and treat |
| High eosinophils + Normal everything else | Parasitic infection or allergy — stool examination recommended |
| Low lymphocytes + Recurrent infections + Weight loss | Consider HIV testing — CD4 count warranted |
8. FBC and Common Nigerian Health Conditions
Malaria
Malaria is the single most common cause of FBC abnormalities in Nigeria. The typical malaria FBC pattern includes:
- Low haemoglobin — malaria destroys red blood cells (haemolysis)
- Low platelet count — often dramatically low, below 100,000/uL
- Variable WBC — may be normal, low (viral-like pattern), or mildly elevated
- Monocytosis — elevated monocytes responding to the parasite
- Absence of eosinophilia — malaria does not cause eosinophilia
Sickle Cell Disease
Nigeria has the highest burden of sickle cell disease in the world. The FBC in sickle cell disease shows:
- Chronic anaemia — haemoglobin typically 6 to 9 g/dL in HbSS patients
- Normocytic or slightly macrocytic anaemia — normal to slightly high MCV
- High reticulocyte count — bone marrow working overtime to replace destroyed cells
- Elevated WBC — especially during crises
- Variable platelet count — may be high (reactive) between crises
- Characteristic sickle-shaped cells on blood film
Typhoid Fever (Salmonella typhi)
- Normal or low WBC (leucopenia) — classically low for a bacterial infection
- Low neutrophils with relative lymphocytosis
- Mild anaemia
- Low platelets in some cases
- Low eosinophils — a useful clue as eosinophilia is absent
HIV Infection
- Low lymphocyte count — particularly CD4 T cells (though standard FBC does not differentiate CD4 from other lymphocytes — a separate CD4 count test is needed)
- Anaemia — from chronic disease, opportunistic infections, or ART side effects
- Thrombocytopenia — immune-mediated platelet destruction
- Leucopenia — bone marrow suppression in advanced disease
Iron Deficiency Anaemia
Iron deficiency is the most common nutritional disorder in Nigeria and the most common cause of anaemia. The FBC shows:
- Low haemoglobin
- Low MCV — microcytic (small) red cells
- Low MCH — hypochromic (pale) red cells
- High RDW — wide variation in cell size as iron-depleted cells get progressively smaller
- Low MCHC
- High platelet count — reactive thrombocytosis often accompanies iron deficiency
9. When Is the FBC Repeated?
| Situation | When to Repeat FBC | What the Repeat Monitors |
| Iron deficiency anaemia on treatment | After 4 to 6 weeks of iron therapy | Response to treatment — haemoglobin should rise by at least 1–2 g/dL |
| Malaria treatment | After completing treatment | Resolution of anaemia and thrombocytopenia |
| Monitoring HIV/ART | Every 3 to 6 months | Anaemia, leucopenia, thrombocytopenia from virus or medication |
| Sickle cell disease | Every 3 to 6 months; more frequently during crisis | Baseline monitoring; severity of crisis |
| Chemotherapy | Before each cycle | Bone marrow recovery — nadir counts after chemotherapy |
| Antenatal care | First trimester, 24–28 weeks, 36 weeks | Monitoring anaemia during pregnancy |
| Recurrent infections | As clinically indicated | WBC trends — immune competence |
| Annual health check | Once yearly in healthy adults | Baseline haematological health |
10. Frequently Asked Questions About the FBC
My FBC shows many parameters. Which ones are most important?
For most patients, the three most clinically important parameters are haemoglobin (assessing anaemia), total WBC count (assessing infection or immune problems), and platelet count (assessing bleeding risk). These three values, read together, tell a doctor the most about your immediate health status. The other parameters provide important detail about WHY these values are abnormal.
My haemoglobin is slightly low but I feel fine. Should I be worried?
Mild anaemia often produces no symptoms at all — particularly if it has developed slowly. Many people adapt to lower haemoglobin levels and feel well. However, feeling fine does not mean the anaemia is harmless. Untreated iron deficiency anaemia, for example, impairs cognitive function, exercise capacity, and immunity — even when there are no obvious symptoms. Always follow up a low haemoglobin result with your doctor to find the cause and receive appropriate treatment.
My WBC is elevated. Does that mean I have an infection?
Not necessarily. While infection is the most common cause of an elevated WBC, other causes include physical or emotional stress, vigorous exercise, steroid medication, smoking, and inflammatory conditions. Looking at which TYPE of white cell is elevated — the differential count — is essential for understanding the meaning. High neutrophils usually mean bacterial infection. High lymphocytes usually mean viral infection or typhoid. High eosinophils usually mean parasites or allergy.
Can I have a normal FBC and still be sick?
Yes. The FBC is a powerful and widely useful test, but it does not detect every medical condition. Many serious conditions — including early kidney disease, liver disease, diabetes, some cancers, and many infections — may produce a completely normal FBC. The FBC is one part of a comprehensive diagnostic evaluation, not a standalone test that rules out all illness.
Does eating or drinking affect my FBC result?
For a standard FBC, fasting is not required. However, drinking large amounts of water or fluid before the test can dilute the blood slightly and lower haemoglobin, PCV, and cell counts marginally. It is best to be normally hydrated — not overly hydrated or dehydrated — when having blood drawn. Vigorous exercise immediately before blood drawing can temporarily raise WBC and platelet counts.
Where can I get a Full Blood Count done in Benin City?
Omokos Diagnostics and Clinical Services Ltd offers Full Blood Count (FBC) testing at our facility in Igo Community, After Ekehuan Barracks, Benin City, Edo State. Our FBC results are accurate, comprehensive, and accompanied by professional interpretation guidance. Walk in or book your appointment at www.omokosdiagnostics.com.ng
Conclusion — Your Blood Count Tells a Story
The Full Blood Count is one of the most powerful diagnostic tools in medicine. In a single blood sample, it tells your doctor about your oxygen-carrying capacity, the strength of your immune system, your ability to stop bleeding, whether you have anaemia and what type, whether you are fighting an infection, whether your bone marrow is functioning normally, and much more.
Understanding your FBC result — even at a basic level — empowers you to be an active participant in your own healthcare. You know what questions to ask your doctor. You understand why certain treatments are prescribed. You recognise when a result is genuinely concerning versus when it is a minor variation.
That knowledge is not just informative. In a healthcare environment where patients often receive results with minimal explanation, it can be life-changing.
Know your numbers. Understand your blood.
Your health depends on it.
Book your Full Blood Count (FBC) today at Omokos Diagnostics and Clinical Services Ltd — Igo Community, After Ekehuan Barracks, Benin City, Edo State. Fast, accurate results with professional care. Visit www.omokosdiagnostics.com.ng
References
1. Bain, B.J. (2015). Blood cells: a practical guide. 5th edition. Oxford: Wiley-Blackwell.
2. World Health Organization (2011). Haemoglobin concentrations for the diagnosis of anaemia and assessment of severity. Geneva: WHO. Available at: www.who.int
3. Nwabuko, O.C., Iwueke, I.P., and Nnaji, G.A. (2018). Haematological indices among Nigerians: establishing reference ranges. Pan African Medical Journal, 31, 142.
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Reviewer’s Note
This article has been reviewed for scientific accuracy, clinical relevance, and suitability for a Nigerian patient audience by Scientist Shuaibu Omoko, Founder of Omokos Diagnostics and Clinical Services Ltd, Benin City. This content is provided for public health education purposes only and does not constitute medical advice. Patients are encouraged to discuss all laboratory results with their qualified healthcare provider.
Scientist Shuaibu Omoko | Founder, Omokos Diagnostics and Clinical Services Ltd
Igo Community, After Ekehuan Barracks, Benin City, Edo State | www.omokosdiagnostics.com.ng
