What is myelofibrosis?
Myelofibrosis (MF) is a chronic blood cancer in which scar tissue builds up in the bone marrow, the “factory” where blood cells are made. As the marrow becomes scarred, it has trouble making normal red blood cells, white blood cells, and platelets, which can lead to anemia, low blood counts, and other symptoms.
MF belongs to a group of conditions called myeloproliferative neoplasms (MPNs), which also include polycythemia vera and essential thrombocythemia. In many people, MF develops slowly over years, and treatment focuses on managing symptoms, improving quality of life, and lowering the risk of complications.
How is myelofibrosis diagnosed?
MF is usually suspected when blood tests show abnormal counts—often anemia (low red blood cells), abnormal white cells, or platelets—and sometimes large, early (“immature”) cells. Your doctor will review your symptoms, examine you for an enlarged spleen or liver, and order more tests.
A bone marrow biopsy is typically needed to confirm MF and see how much scar tissue is present. Genetic testing may look for common driver mutations (such as JAK2, CALR, or MPL) and other changes that help classify your disease and guide treatment decisions.
What symptoms should I watch for?
Some people have few symptoms when MF is found, while others notice problems that slowly worsen over time. Common symptoms include fatigue, weakness, shortness of breath, frequent infections, night sweats, weight loss, bone pain, and a feeling of fullness or discomfort under the left ribs from an enlarged spleen.
You may also have fevers, itching, abdominal pain, or early satiety (feeling full after just a few bites), which can affect your appetite and weight. Tell your care team about any new or worsening symptoms, because they can signal that your MF is changing or that your treatment needs to be adjusted.
How serious is myelofibrosis?
MF is a serious illness, but it behaves very differently from person to person. Some people live with stable disease and manageable symptoms for many years, while others have a more aggressive course and may need more intensive treatment or even a stem cell (bone marrow) transplant.
Doctors use risk scores that consider your age, blood counts, symptoms, genetic changes, and other lab results to estimate prognosis. Newer treatments, especially JAK inhibitor medicines, have improved symptoms and survival for many people, so your individual outlook is best discussed with your own MF specialist.
What are the main risks and complications of MF?
Important complications of MF include anemia, low white blood cells, low platelets, and a very enlarged spleen, which can cause pain, fullness, or early satiety. These issues can lead to fatigue, infections, easy bruising or bleeding, and weight loss.
In some patients, MF can progress to acute myeloid leukemia (AML), a fast‑growing blood cancer that requires different treatment. Because of these risks, regular monitoring and timely treatment changes are an important part of care.
What treatments are available for myelofibrosis?
Treatment depends on your symptoms, risk level, blood counts, and overall health. Options include:
- Watchful waiting (close monitoring) if you have few symptoms and low‑risk disease.
- JAK inhibitor medicines such as ruxolitinib, fedratinib, pacritinib, and momelotinib to shrink the spleen, improve symptoms, and in some people improve survival.
- Supportive care such as blood transfusions, medications to boost blood counts, antibiotics for infections, and symptom‑relief measures.
- Stem cell (bone marrow) transplant, the only treatment that can potentially cure MF, for selected patients who are healthy enough and have higher‑risk disease.
Your team may also recommend clinical trials that test new drugs or combinations.
What are JAK inhibitors and how do they help?
Many people with MF have changes in the JAK‑STAT pathway, which tells bone marrow cells to grow and make blood cells. JAK inhibitors are pills that block this overactive signaling and can reduce inflammation, shrink the spleen, and ease symptoms like fatigue, night sweats, and bone pain.
Four JAK inhibitors—ruxolitinib, fedratinib, pacritinib, and momelotinib—are FDA‑approved for MF, each with slightly different benefits and side effect profiles. Your doctor will consider your platelet count, anemia, prior treatments, and other health conditions when choosing which one to start or switch to.
When is stem cell (bone marrow) transplant considered?
Stem cell transplant replaces your diseased bone marrow with healthy donor cells and offers the best chance for long‑term remission or cure. However, it also carries significant risks, including serious infections, graft‑versus‑host disease, and even treatment‑related death, so it is not right for everyone.
Transplant is usually considered for younger, fitter patients with higher‑risk MF, especially those with certain high‑risk mutations or rapidly worsening disease. If transplant is an option, you will meet with a transplant team to discuss timing, donor search, and how it fits with other treatments like JAK inhibitors.
How often will I need blood tests and follow‑up?
People with MF are followed regularly so that doctors can track symptoms, spleen size, and blood counts. Early on or when changing treatment, visits and labs may be more frequent; if your disease is stable, you may be seen every few months.
At each visit, expect a review of your symptoms and medications, a physical exam (including your spleen), and blood tests; sometimes imaging or bone marrow biopsies are needed to reassess your disease. Keeping all scheduled appointments and labs helps your team adjust treatment before problems become severe.
What side effects should I know about from MF treatments?
JAK inhibitors can cause or worsen low blood counts (anemia, low platelets), bruising, infections, headaches, or stomach upset; specific risks vary by drug. Your doctor will check blood tests regularly and may adjust the dose, pause treatment, or switch medicines if side effects become a problem.
Other treatments, such as blood transfusions or steroids, have their own potential side effects, including iron overload or blood sugar changes. Before starting any treatment, ask what to expect, which symptoms are urgent, and when to call your care team.
Can lifestyle changes make a difference?
Healthy habits cannot cure MF, but they can help you feel better and may lower your risk of complications. Common recommendations include not smoking, staying physically active as you are able, eating a balanced diet, maintaining a healthy weight, and staying current on vaccines after discussing them with your doctor.
Because fatigue is so common, pacing your activities, planning rest periods, and asking for help with heavy tasks can make daily life more manageable. Gentle exercise, such as walking or stretching, can sometimes improve energy and mood; ask your team what is safe for you, especially if your spleen is enlarged or your counts are low.
How might MF affect surgery, dental work, or other procedures?
MF and its treatments can affect your bleeding and infection risk, so it is important that all of your providers know about your diagnosis and medications. Before planned surgery or dental work, your hematologist may recommend adjusting blood‑thinning drugs, JAK inhibitors, or other medicines.
In some cases, you may need extra blood tests, transfusions, or antibiotics before and after procedures to lower risk. Ask your hematologist for a written summary of your MF and treatments that you can share with other doctors and dentists.
Should I consider joining a clinical trial?
Clinical trials are research studies that test new ways to treat or monitor MF and may offer access to promising therapies not yet widely available. Trials may involve new drugs, new combinations of existing medicines, or different transplant approaches.
Not everyone will be eligible or interested, but asking about trials at major cancer centers or academic hospitals can help you understand your options. Your care team can help you weigh the potential benefits and risks and decide if a trial fits your goals and situation.
How can I cope emotionally with a myelofibrosis diagnosis?
Living with a chronic blood cancer can bring worry, sadness, anger, or fear about the future, even when your disease is stable. Many people find it helpful to learn about MF from trusted sources, bring questions to appointments, and include a family member or friend in important visits.
Support groups (online or in person), counseling, and connections with other people living with MF or MPNs can provide understanding and practical tips. Let your team know if you feel overwhelmed, anxious, or depressed so they can connect you with social workers, mental health professionals, or spiritual care resources.
Where can I find reliable information and support?
Reliable information is available from national cancer organizations, MPN advocacy groups, and patient‑focused guidelines. These resources offer booklets, videos, symptom trackers, and tools to help you prepare for visits and understand your treatment options.
Join the conversation on CancerConnect to share your experience, ask a question and connect with others living with MF. CancerConnect has been supporting, empowering, and connecting patients and caregivers since 1997. CancerConnect combines a moderated community, daily cancer news, and educational resources.
This “Ask the Expert” FAQ is for education only and is not a substitute for medical advice. Always discuss your own situation, test results, and treatment options with your healthcare team.
More Reading
Overview of Myeloproliferative Neoplasms
Myeloproliferative Neoplasms and Fatigue
Depression Is Not “Just in Your Head”: Spotting and Treating Hidden Mood Changes in MPNs
