Red Cell Parameters
| Parameter | Normal (Adult) | What It Means When Abnormal |
|---|---|---|
| Haemoglobin (Hb) | M: 130–170 g/L; F: 115–155 g/L | Low: anaemia. High: polycythaemia |
| Red cell count (RBC) | M: 4.5–5.5; F: 3.8–5.0 (×10¹²/L) | Counts red cells directly |
| MCV (mean corpuscular volume) | 80–100 fL | Low (<80): iron/thalassaemia. High (>100): B12/folate/alcohol/liver |
| MCH (mean corpuscular haemoglobin) | 27–33 pg | Parallels MCV — reflects cell haemoglobin content |
| MCHC | 315–360 g/L | Very low = iron deficiency. Very high = spherocytosis |
| RDW (red cell distribution width) | 11.5–14.5% | High = mixed anaemia (iron + B12) or early iron deficiency |
White Cell Parameters
| Parameter | Normal | High = | Low = |
|---|---|---|---|
| Total WBC | 4.0–11.0 × 10⁹/L | Infection, inflammation, leukaemia | Bone marrow failure, viral illness, drugs |
| Neutrophils | 1.8–7.5 × 10⁹/L | Bacterial infection, steroids, stress | Viral illness, drugs, autoimmune (neutropenia) |
| Lymphocytes | 1.0–4.0 × 10⁹/L | Viral infection, CLL | HIV, steroids, autoimmune, SARS-CoV-2 |
| Eosinophils | 0.04–0.4 × 10⁹/L | Allergy, asthma, parasites, eosinophilic conditions | Rarely significant |
| Monocytes | 0.2–0.8 × 10⁹/L | Chronic infection, TB, inflammatory bowel disease | Rarely significant |
| Basophils | 0–0.1 × 10⁹/L | CML, allergic states | Rarely significant |
Platelets: More Than ClottingLow platelets (<100) can mean ITP, splenomegaly, bone marrow suppression, or DIC. Very high platelets (>600) may indicate reactive thrombocytosis (infection, iron deficiency) or essential thrombocythaemia.
What does a high MCV mean?
High MCV (macrocytosis) means red cells are abnormally large. Causes: B12 or folate deficiency, alcohol excess, hypothyroidism, liver disease, drugs (methotrexate, hydroxycarbamide). Always check B12 and folate.
What causes low neutrophils (neutropenia)?
The most common causes are viral illness (EBV, CMV, COVID), drug-induced (chemotherapy, certain antibiotics, antithyroid drugs), autoimmune, or severe infection consuming neutrophils.
What is a left shift?
Left shift = increased proportion of immature neutrophils (band forms, metamyelocytes) in the blood, indicating rapid neutrophil production — seen in severe bacterial infection or bone marrow stress.
Can I interpret my own FBC?
You can understand the general direction, but always discuss with your doctor. Many results are normal variants; the clinical context (symptoms, other results, trends) is essential to interpretation.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.