Myelofibrosis: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Myelofibrosis?
A hematologist, a doctor who treats diseases of the blood and bone marrow, usually leads care for myelofibrosis. It is a disorder in which scar tissue replaces the bone marrow. 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 myelofibrosis?
Myelofibrosis is a disorder of the bone marrow in which the marrow is replaced by fibrous scar tissue. Bone marrow is the soft, fatty tissue inside your bones. It holds stem cells, which are immature cells that develop into all of your blood cells.
When the bone marrow is scarred, it cannot make enough blood cells. Anemia, bleeding problems and a higher risk for infections may occur. Anemia is a shortage of red blood cells.
As a result, the liver and spleen try to make some of these blood cells. This causes these organs to swell.
Myelofibrosis belongs to a group of diseases called myeloproliferative neoplasms. These diseases may also be classified as blood cancers. Primary myelofibrosis is rare, affecting approximately 1 in 500,000 people worldwide.
Symptoms
Initially, most people with primary myelofibrosis have no symptoms.
Symptoms may include any of the following:
- Feeling full before finishing a meal, or belly fullness or pain, because of an enlarged spleen.
- Bone pain.
- Easy bleeding or bruising.
- Fatigue (extreme tiredness).
- More infections than usual.
- Pale skin.
- Shortness of breath with exercise.
- Weight loss.
- Night sweats and a low grade fever.
- An enlarged liver, a dry cough or itchy skin.
Causes and who gets it
The cause of myelofibrosis is often unknown, and there are no known risk factors.
Changes (mutations) in the JAK2, MPL, CALR and TET2 genes are linked to most cases of primary myelofibrosis. The condition is generally not inherited. The gene changes happen in early blood-forming cells after conception.
Blood and bone marrow cancers, such as myelodysplastic syndrome, leukemia and lymphoma, may also cause bone marrow scarring. This is called secondary myelofibrosis.
It often develops slowly in people over age 50. Primary myelofibrosis is most commonly diagnosed in people aged 50 to 80 but can occur at any age. It occurs more often in Ashkenazi Jews.
How doctors diagnose it
The provider does a physical exam and asks about your symptoms. In many people, the first signs are an enlarged spleen or anemia.
Tests that may be done include:
- A complete blood count (CBC) with a blood smear, which checks the different types of blood cells.
- A blood test of the LDH enzyme level, which measures tissue damage.
- A bone marrow biopsy, in which a small sample of bone marrow is removed and examined. It is often used to confirm the diagnosis.
Treatment
Treatment is planned for each person, based on symptoms, how severe the disease is, blood counts, overall health and risk group.
Options include:
- Watchful waiting. If you have no symptoms at diagnosis, doctors may suggest careful monitoring instead of treatment right away.
- Blood transfusions and medicines to correct anemia.
- JAK inhibitor medicines, which have significantly changed the treatment of myelofibrosis. They can reduce spleen size, improve symptoms such as fatigue and night sweats, and improve quality of life. The FDA approved ruxolitinib (Jakafi) in 2011, fedratinib (Inrebic) in 2019, pacritinib (Vonjo) in 2022, and momelotinib (Ojjaara) in 2023.
- Hydroxyurea, which may help control high white blood cell counts, high platelet counts and enlarged organs. It does not reverse the underlying disease.
- Removal of the spleen (splenectomy) or radiation to the spleen, when an enlarged spleen causes severe symptoms that do not respond to medicine. These can give temporary improvement but carry significant risks.
- Stem cell transplant, in which healthy blood-forming stem cells from a donor replace the diseased bone marrow. It is the only treatment that offers a cure, but it carries a high risk of serious and potentially life-threatening complications. It is typically reserved for younger people or those with high-risk disease.
Treatment choices are best made with your health care team.
When to see a doctor
Make an appointment with your provider if you have symptoms of this disorder. Seek medical care right away for jaundice (yellow skin and whites of the eyes) that gets worse.
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, such as confusion.
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. A direct primary care doctor can order blood tests, send you to a hematologist, and help track your health between specialist visits.
Common questions
Is myelofibrosis a cancer?
It may be classified as a blood cancer. Myelofibrosis belongs to a group of diseases called myeloproliferative neoplasms.
Can myelofibrosis be cured?
Only a stem cell transplant offers a cure, and it is not right for everyone. Other treatments can help control symptoms, but they do not reverse the underlying disease.
Can myelofibrosis turn into leukemia?
Yes, a type of blood cancer called acute myelogenous leukemia is a possible complication. Others are infections, bleeding, blood clots and liver failure.
How long do people live with myelofibrosis?
It varies, and some people survive for decades. In a large U.S. database, about half of people with primary myelofibrosis lived more than 5 years after diagnosis.
Sources
- MedlinePlus - Myelofibrosis (Medical Encyclopedia)
- MedlinePlus Genetics - Primary myelofibrosis
- NORD - Primary Myelofibrosis
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.
