Complete blood count (CBC): what the basic blood count means
Marker explained · Complete blood count (CBC)

Complete blood count (CBC): what the basic blood count means

Part of the guide: Complete blood count (CBC) →

In short

  • A CBC looks at red and white blood cells, haemoglobin and platelets.
  • Low haemoglobin = anaemia (often iron, B12 or folate deficiency).
  • Raised white cells often go with infection/inflammation.
  • Always judge values in context; a doctor assesses deviations.

The basic blood count (CBC or haemogram) is one of the most common reports. It says a surprising amount about your health — from anaemia to signs of infection.

What a CBC contains

ComponentWhat it tells you
Haemoglobin (Hb)oxygen transport; low = anaemia
Erythrocytesred blood cells (number, size — MCV)
Leukocyteswhite blood cells; defence against infection
Plateletsblood platelets; clotting

Reference limits depend on sex and laboratory. Judge them against the range on your own report.

What common deviations mean

Low haemoglobin (anaemia)

The blood carries less oxygen. You feel tired, look pale and get out of breath. The size of the cells (MCV) helps separate the cause. Small cells often mean iron deficiency, large ones B12/folate deficiency.

Raised white cells

Often a sign of infection or inflammation. We judge them together with how you feel and your other results.

Platelets

Too low or too high belongs in a doctor's assessment — platelets matter for clotting.

In practice: a CBC is an excellent screening test. When something is unclear, targeted tests fill in the picture (ferritin, B12, folate, inflammation markers).

When to see a doctor. Marked deviations belong with a doctor to assess the cause. Examples: very low haemoglobin or an unusual number of white cells/platelets.

How Blood Lab 360 helps

We explain the blood count in plain language. We link it with other markers to find the cause of, say, tiredness. And we track your progress over time.

Frequently asked questions

What does low haemoglobin mean?

Anaemia — the blood carries less oxygen. Common causes: iron, B12 or folate deficiency.

What do raised white blood cells mean?

Often infection or inflammation; they need to be judged in context.

What are platelets?

Blood platelets for clotting; too low or too high belongs in a doctor's assessment.

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Sources

  1. MedlinePlus (NIH): Complete Blood Count (CBC) (2024)
  2. WHO: Guideline on haemoglobin cutoffs to define anaemia in individuals and populations (2024)

Links checked on 14 Sep 2026. The marker ranges above carry their own source next to each row.

Related

This article is for information only and is not a substitute for medical advice. Talk to your doctor about your results.

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