White blood cells: what are the standard values

By Cristiano Antonino On Jan 12, 2023

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White blood cells (or leucocytes) are spheroidal, nucleated elements that defend the body against infection. White blood cells do not contain haemoglobin and are in a 1:1 ratio with red blood cells

White blood cells, standard values

Normal values range from 4,500 to 11,000 per µL.

The composition of white blood cells (leucocyte formula) is as follows:

Neutrophils: 70-80%
Lymphocytes: 20-30%
Monocytes: 6-8%
Eosinophils: 1-4%
Basophils: 0-1%.

An alteration in white blood cells is a warning sign that should not be underestimated

It is very important to know which type has increased in order to establish what type of infection is present.

An increase in neutrophils (neutrophilia) is an indication of acute infection, chronic inflammation, leukaemic reactions, myocardial infarction.

A decrease (neutropenia) can be caused by high destruction due to autoimmune diseases or reduced production, usually caused by taking drugs (cytotoxics, immunosuppressants, antibiotics), viral infections or haematological diseases, prolonged exposure to X-rays.

The increase in lymphocytes (lymphocytosis) occurs following acute viral infectious diseases, chronic infections and lymph and liver leukaemias.

The decrease (lymphopenia) may be due to hereditary or acquired immunodeficiency (AIDS), lymphomas, aplastic anaemia, collagenopathies and tuberculosis in active phase.

An increase in monocytes (monocytosis) is indicative of myeloproliferative syndromes (leukaemias, lymphomas, myelomas, histiocytoses), chronic infections, autoimmune diseases, malignant neoplasms, and gastrointestinal disorders.

A decrease (monocytopenia) is caused by diseases associated with pancytopenia.

An increase in eosinophils (eosinophilia) is a symptom of allergic and parasitic diseases.

A decrease (eosinophilopenia) may be associated with stress, corticosteroid treatment or Cushing’s disease.

An increase in basophils (basophilia) may be due to chronic myeloid leukaemia, polycythaemia, ulcerative colitis, rheumatoid arthritis, iron deficiency, neoplasms, infections, metabolic diseases.