Leukocytosis: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Leukocytosis?
A primary care doctor can find a high white blood cell count on a blood test and look for the cause. Depending on the cause, you may be sent to a hematologist (a doctor who treats blood disorders) or another specialist. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is leukocytosis?
Leukocytosis is a higher-than-normal white blood count. White blood cells, also called leukocytes, are part of your immune system. They are made in your bone marrow and found in your blood and lymph tissue.
When you are injured or get sick, white blood cells travel through your bloodstream and tissues to where they are needed. There, they help your body fight off infections and other diseases. When you get sick, your body makes more of them, which raises your white blood count.
There are five major types of white blood cells: neutrophils, lymphocytes, monocytes, eosinophils, and basophils. A test called a blood differential shows the amount of each type. Neutrophils mostly target bacterial infections. Lymphocytes mostly target viral infections.
Symptoms
A white blood count is a lab result, so you find out about a high count from a blood test. You may be tested if you have signs of an infection, inflammation, or an autoimmune disease. An autoimmune disease is a condition that makes the immune system attack healthy tissue.
Symptoms of an infection may include:
- Fever.
- Chills.
- Body aches.
- Headache.
- A wound that is red, has pus, or will not heal.
- An ongoing cough.
The symptoms of inflammation and autoimmune diseases depend on where in the body the inflammation is and which disease you have.
Causes and who gets it
Conditions that may cause a high white blood count include:
- An infection, most often one caused by bacteria.
- An inflammatory disease such as rheumatoid arthritis, or an allergy.
- Leukemia or Hodgkin disease.
- Tissue damage, such as from a burn.
- Severe emotional or physical stress, such as from an injury or surgery.
- Pregnancy.
- Cigarette smoking.
- Surgery to remove the spleen.
Some medicines may also raise the count. These include corticosteroids, epinephrine, heparin, lithium, albuterol and similar medicines, and granulocyte colony stimulating factor.
How doctors diagnose it
A white blood count is a blood test that measures the number of white blood cells in your blood. It is part of a complete blood count, or CBC, which also measures red blood cells and platelets. A health care professional takes a blood sample from a vein in your arm with a small needle. For babies, the sample may come from the heel instead. For older babies and children, it may come from a fingertip or the arm.
The normal number of white blood cells is 4,500 to 11,000 per microliter of blood. Normal ranges can vary slightly between labs. You usually do not need any special preparation, but tell your provider about all the medicines you take, because some medicines can change the result.
A white blood count can show that the number is too high, but it cannot confirm a diagnosis. So your provider usually orders other tests too. These can include a blood differential and a bone marrow test. Your provider looks at your symptoms, medical history, and other blood tests to understand the result.
Treatment
A high white blood count is a test result that needs context. Your provider considers your medical history, your symptoms, and other factors before deciding what it means. If any blood count is abnormal, it does not always mean you have a medical condition that needs treatment.
Diet, activity level, medicines, and not drinking enough water can affect blood test results. Tell your provider about everything you take. Do not stop taking any medicine unless your provider tells you to.
When to see a doctor
You may need a white blood count if you have signs of an infection, such as fever, chills, body aches, a wound that will not heal, or an ongoing cough, so talk to your provider. Also talk to your provider about any blood test result you do not understand.
Call 911 or go to the emergency room if you have bleeding that will not stop, trouble breathing, chest pain, fainting, or a sudden change in mental state.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Such a doctor can review your blood test results, your symptoms, and the medicines you take. They can also order follow-up tests and refer you to a specialist when needed.
Common questions
What is a normal white blood cell count?
The normal number of white blood cells is 4,500 to 11,000 per microliter of blood. Normal ranges can vary slightly between labs, so ask your provider what your result means.
Does a high white blood count mean I have leukemia?
No, a high white blood count does not always mean leukemia. Infections, inflammatory disease, allergies, smoking, stress, some medicines, and pregnancy can also cause it.
Can medicines cause a high white blood count?
Yes, some medicines may raise your white blood count. Examples include corticosteroids, epinephrine, heparin, and lithium. Do not stop a medicine unless your provider tells you to.
Can stress or smoking raise my white blood count?
Yes, severe emotional or physical stress, such as from an injury or surgery, may raise your white blood count. Cigarette smoking may also raise it.
Sources
- MedlinePlus - White Blood Count (WBC)
- MedlinePlus - WBC count (Medical Encyclopedia)
- MedlinePlus - Complete Blood Count (CBC)
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
