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Medically reviewed by Last updated on Oct 1, 2023.

What is leukocytosis?

Leukocytosis is a condition that causes you to have too many white blood cells (WBC). WBCs are part of your immune system and help fight infections and diseases.

What causes or increases my risk for leukocytosis?

  • Infections, inflammation, or tissue damage
  • Immune reactions, such as during an asthma or allergy attack
  • Bone marrow problems, such as leukemia or thrombocytopenia
  • Medicines used to treat inflammation, mental health disorders, cancer, or breathing problems
  • Physical or emotional stress

What are the signs and symptoms of leukocytosis?

You may not have any signs or symptoms. Symptoms are often from the cause of the leukocytosis. The following are common symptoms:

  • Fever
  • Bleeding or bruising
  • Feeling weak, tired, or sick
  • Feeling dizzy, faint, or sweaty
  • Pain or tingling in your arms, legs, or abdomen
  • Trouble breathing, thinking, or seeing
  • Losing weight without trying, or a poor appetite

How is leukocytosis diagnosed?

Your healthcare provider may ask about your medical history. Your provider will also ask what medicines you take, and if you have any allergies. Blood tests will show the number and shape of your WBCs. They will show if you have too much of one type of WBC. They may also help to find the cause of your leukocytosis. You may also need a bone marrow test to find the cause of your leukocytosis.

How is leukocytosis treated?

Your WBCs may return to normal without treatment. Your healthcare provider will treat the cause of your leukocytosis. You may also need any of the following:

  • IV fluids may be given to give you extra fluid and electrolytes.
  • Medicines may be given to decrease inflammation or treat an infection. You may also be given medicine to decrease acid levels in your body or urine.
  • Leukapheresis is a procedure to decrease the number of WBCs. Blood is taken from your body through an IV. The WBCs are separated and removed. Your blood, without the WBCs, may be given back to you, or sent to a lab for tests.

Call your local emergency number (911 in the US) if:

  • You have any of the following signs of a stroke:
    • Numbness or drooping on one side of your face
    • Weakness in an arm or leg
    • Confusion or difficulty speaking
    • Dizziness, a severe headache, or vision loss
  • You have chest pain or trouble breathing.

Seek immediate care if:

  • You have bleeding that does not stop.
  • You have new pain or tingling in your arms, legs, or abdomen.
  • You have sudden back pain.

When should I call my doctor?

  • You have a fever.
  • You bruise or bleed easily.
  • You have weight loss without trying or a poor appetite.
  • You feel nauseated.
  • You feel weak, tired, or sick.
  • You are a man and you have a painful erection that lasts longer than usual.
  • You have questions or concerns about your condition or care.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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