Myelofibrosis (MF) symptoms

Some people don’t have any symptoms at all when they are diagnosed with myelofibrosis (MF). Others will have more obvious symptoms.

It’s important to realise that there isn’t always a direct link between the level of symptoms and the stage of the disease. It depends on you, your blood counts, and what’s happening in your bone marrow.

Common symptoms include:

• extreme tiredness (fatigue)
• losing weight without trying
• drenching night sweats
• unexplained fever
• itching, sometimes particularly after a hot bath or shower
• general weakness
• feeling full up very quickly when trying to eat.

Other symptoms will depend on the number of blood cells your bone marrow is making. You may have high blood counts (too many blood cells) or low blood counts (too few blood cells).

You may have high levels of white blood cells or platelets if you have myelofibrosis (MF). This is more likely to happen in the prefibrotic stage (before there is any scarring of the bone marrow) or in the earlier stages of overt MF.

Having too many platelets means your blood may clot too easily. Blood clots can cause a range of problems, depending on which blood vessels are affected:

• In the brain, clots can cause stroke or mini stroke (known as a TIA or transient ischaemic attack).
• In the eyes, clots can cause blurred vision or loss of sight.
• In the heart, they can cause a heart attack.
• In the stomach area (abdomen), they can cause damage to organs such as your liver and gut.
• In the legs, they can cause deep vein thrombosis (DVT). If you have DVT there is a chance that a clot in your leg can break free and travel to your lungs. This is called a pulmonary embolism.

All of these things can cause serious problems and some are life-threatening. So it’s important to be aware of the symptoms of thrombosis. These will vary depending on where the clot is, but they include:

• slurred speech
• weakness on one side of the body
• drooping on one side of your face
• sudden chest pain, dizziness and feeling short of breath
• one leg or arm becoming painful, swollen and warm
• coughing up blood
• sudden blurred vision or loss of sight
• sudden pain in the stomach area, possibly with tummy swelling and signs of jaundice (a yellowing of the eyes, and yellowish skin in people with lighter skin tones).

If you have one or more of these symptoms, it’s a medical emergency. Call 999 and get medical help straight away.

If the number of platelets in your blood is very high, there is also a risk of unusual bleeding (haemorrhage). It may seem odd that having too many platelets can cause bleeding as well as blood clotting. But bleeding can happen when the number of platelets is very high, and they don’t work normally.

If you are diagnosed with MF you will have regular check-ups, including blood tests to monitor your blood cell counts. If you are at risk, you will have treatment to lower the risk of thrombosis or bleeding. See our page about treatment.

Low levels of blood cells can lead to a range of symptoms:

• Too few red blood cells can make you feel tired, breathless and dizzy. The medical name for this is anaemia.
• Too few white blood cells can mean you get more infections like colds and flu, chest and urinary tract infections. These may last longer and be more serious than usual.
• Too few platelets can lead to bruising and unusual bleeding such as nose bleeds and heavy periods.

Treatment for myelofibrosis will aim to relieve the symptoms of too few blood cells by boosting the number of blood cells your body makes. You may also be given blood transfusions.

The spleen is a fist-sized organ that sits to the left of the stomach, behind the ribs. It plays an important role in your immune system. One of its jobs is to make blood cells, although it’s not as efficient at doing that as the bone marrow.

If your bone marrow can’t make enough blood cells, your spleen will start to work overtime. This could cause symptoms in your stomach (tummy) area including:

• a feeling of discomfort or pain
• feeling full very quickly when you eat because the swollen spleen is pressing on your stomach
• feeling sick or being sick (vomiting).

Treatment for myelofibrosis will help with the symptoms of a swollen spleen.

A few people may have bone pain. This can happen at any stage but is more likely at a later stage of myelofibrosis (MF) when there is more scarring (fibrosis) and more inflammation in the bone marrow. See What is myelofibrosis? for more information about bone marrow scarring.

If you have significant bone pain, your hospital team may treat you with JAK inhibitors, sometimes along with drugs called bisphosphonates which can help to strengthen your bones.