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Leukocytosis

February 19, 2026
Topic

A high level of white blood cells in the blood. Causes of a high white blood cell count can be infection, reaction to a medicine, a bone marrow condition, an immune system issue, smoking or sudden stress such as hard exercise.

See a healthcare professional right away for the following symptoms:

  • Lasting fever.
  • High pulse rate.
  • Night sweats.

Make an appointment to see a healthcare professional for:

  • Greater tiredness.
  • Repeat infections.