Leukocytosis means you have more white blood cells than normal. White blood cells are made in your bone marrow. The main job of white blood cells is to fight infection. Having too many white blood cells is a common condition. It can develop as a result of many types of medical problems.


In some cases, your bone marrow may be normal, but it is still making too many white blood cells. This could be the result of:

  • Infection.

  • Injury.

  • Physical stress.

  • Emotional stress.

  • Surgery.

  • Allergic reactions.

  • Tumors that do not start in the blood or bone marrow.

  • An inherited disease.

  • Certain medicines.

  • Pregnancy and labor.

In other cases, you may have a bone marrow disorder that is causing your body to make too many white blood cells. Bone marrow disorders include:

  • Leukemia. This is a type of blood cancer.

  • Myeloproliferative disorders. These disorders cause blood cells to grow abnormally.


Some people have no symptoms. Others have symptoms due to the medical problem that is causing their leukocytosis. These symptoms may include:

  • Bleeding.

  • Bruising.

  • Fever.

  • Night sweats.

  • Repeated infections.

  • Weakness.

  • Weight loss.


Leukocytosis is often found during blood tests that are done as part of a normal physical exam. Your caregiver will probably order other tests to help determine why you have too many white blood cells. These tests may include:

  • A complete blood count (CBC). This test measures all the types of blood cells in your body.

  • Chest X-rays, urine tests (urinalysis), or other tests to look for signs of infection.

  • Bone marrow aspiration. For this test, a needle is put into your bone. Cells from the bone marrow are removed through the needle. The cells are then examined under a microscope.


Treatment is usually not needed for leukocytosis. However, if a disorder is causing your leukocytosis, it will need to be treated. Treatment may include:

  • Antibiotic medicines if you have a bacterial infection.

  • Bone marrow transplant. Your diseased bone marrow is replaced with healthy cells that will grow new bone marrow.

  • Chemotherapy. This is the use of drugs to kill cancer cells.


  • Only take over-the-counter or prescription medicines as directed by your caregiver.

  • Maintain a healthy weight. Ask your caregiver what weight is best for you.

  • Eat foods that are low in saturated fats and high in fiber. Eat plenty of fruits and vegetables.

  • Drink enough fluids to keep your urine clear or pale yellow.

  • Get 30 minutes of exercise at least 5 times a week. Check with your caregiver before starting a new exercise routine.

  • Limit caffeine and alcohol.

  • Do not smoke.

  • Keep all follow-up appointments as directed by your caregiver.


  • You feel weak or more tired than usual.

  • You develop chills, a cough, or nasal congestion.

  • You lose weight without trying.

  • You have night sweats.

  • You bruise easily.


  • You bleed more than normal.

  • You have chest pain.

  • You have trouble breathing.

  • You have a fever.

  • You have uncontrolled nausea or vomiting.

  • You feel dizzy or lightheaded.


  • Understand these instructions.

  • Will watch your condition.

  • Will get help right away if you are not doing well or get worse.