Polycythaemia vera: symptoms, treatment and outlook

Having a high number of red blood cells does not always cause symptoms. Macmillan says some people are diagnosed after a blood test for another reason, and Leukaemia Care says around half of people have no symptoms at diagnosis. Blood Cancer UK says you will not have all the possible symptoms and may have none.

Blood Cancer UK explains that over-production of blood cells makes the blood thicker than normal and harder to flow smoothly through blood vessels, and that this causes most of the symptoms.

• Severe, migraine-type headaches, dizziness, confusion or changes in vision.

• Feeling very tired (fatigue).

• Itchy skin, often after a warm bath or shower.

• Sweating more than usual, fevers or drenching night sweats.

• Burning pain, change in feeling or redness in the hands or feet; cold or blue fingers or toes.

• Red-looking face, skin or eyes (Blood Cancer UK notes this may be harder to see on darker skin).

• Bone or joint pain, unexplained weight loss.

• Discomfort in the tummy and feeling full soon after starting to eat, which can be due to an enlarged spleen.

Macmillan lists several complications. A higher risk of blood clots is the most important, and clots can cause heart attacks and strokes. An enlarged spleen on the left side of the tummy can cause discomfort and a feeling of fullness. When the body breaks down more blood cells than usual, uric acid can build up and cause gout. Abnormal bleeding or bruising can also occur, including nosebleeds, bleeding gums, heavy periods and blood in pee or poo.

A very small number of people with PV develop myelofibrosis (scarring of the bone marrow), and rarely acute myeloid leukaemia. Leukaemia Care gives general figures: between 5 and 6 in every 100 people with PV develop myelofibrosis within 10 years of diagnosis, and between 2 and 3 in every 100 develop acute myeloid leukaemia within 10 years. Blood Cancer UK says the risk is low for everyone, but there is some evidence it increases the longer you have PV.

Blood Cancer UK says that symptoms of a blood clot are a medical emergency. Macmillan says if you have symptoms such as throbbing pain, redness or swelling in a leg or arm, sudden breathlessness or coughing, or sharp chest pain, contact the hospital straight away or call NHS 111 if you cannot speak to your doctor. If you think you may be having a heart attack or stroke, call 999 or go straight to A&E.

Macmillan also says to contact a doctor urgently if you see blood in your vomit or poo, have very dark poo, or if bleeding is heavy or will not stop, and to call 999 or go to A&E if you cannot reach a doctor.

• Face drooping, slurred speech or weakness on one side of the body.

• Sudden chest pain, dizziness or shortness of breath, or coughing up blood.

• One leg or arm becoming painful, swollen and warm.

• Sudden blurred vision or loss of sight.

• Heavy bleeding that will not stop, or blood in vomit or poo.

There is no cure, but Blood Cancer UK says it can be treated effectively and treatment can help control symptoms. Macmillan explains that a multidisciplinary team plans treatment after looking at the risk of problems from PV. The PV is described as low, intermediate or high risk depending on age, symptoms, other medical conditions, blood counts, genetic changes, blood thickness (haematocrit) and previous blood clots.

Treatment is usually given to prevent problems such as blood clots (supportive treatment), and can also be given to reduce red blood cell numbers (cytoreductive therapy). You will have regular blood tests to check for changes, and may be offered treatment as part of a clinical trial.

Lifestyle advice from Macmillan includes giving up smoking, drinking plenty of fluids, eating healthily, being physically active, keeping to a healthy weight, managing stress, and treating conditions such as diabetes, high blood pressure and high cholesterol.

Macmillan describes PV as a type of blood cancer that affects the bone marrow, where blood cells are made. In PV the body makes too many red blood cells, which can make the blood thicker than normal. Some people also have too many white blood cells and platelets.

It can happen at any age. Macmillan says it is more common in people aged over 40 and slightly more common in men, while Leukaemia Care says it is more common in people over 60. It belongs to the family of myeloproliferative neoplasms, which also includes essential thrombocythaemia and myelofibrosis.

Leukaemia Care says the exact cause is not known and PV is not usually inherited, so you cannot usually pass it on to your children.

Macmillan says a GP might suspect PV if a full blood count (FBC) shows a raised number of blood cells over a period of time. If your doctor thinks you may have PV, you will be referred to a haematologist, a specialist blood doctor, and may meet a clinical nurse specialist who can be your key worker.

The haematologist decides whether further tests are needed.

• More blood tests, including a blood test for the JAK2 gene change (about 95 in 100 people with PV have it).

• A bone marrow biopsy, usually from the back of the hip bone.

• A red cell mass test and plasma volume study, using a small amount of radioactivity.

• Iron, vitamin B12 and erythropoietin levels, to rule out other causes.

• Pulse oximetry to measure oxygen in the blood, and an ultrasound scan if the spleen is enlarged.

Macmillan says PV develops slowly and for most people will not shorten their lives. Blood Cancer UK says your outlook depends on individual factors such as your age and fitness, whether you have had blood clots, and which genetic mutation you have, and that your haematologist is the best person to ask. Leukaemia Care says people with PV who do not develop another type of blood cancer usually have excellent outcomes and only a slightly reduced life expectancy.

Macmillan says to talk to your doctor first if you are planning to become pregnant, because chemotherapy and some other treatments may affect an unborn baby and may affect fertility. PV can raise the risk of complications in pregnancy, but with risk-reducing treatment and careful monitoring most babies are born healthy. Daily aspirin is usually advised in pregnancy.

You will need regular check-ups and blood tests. Tell your haematologist or clinical nurse specialist if you notice new symptoms between appointments.

On the NHS, PV is usually picked up through a GP blood test, followed by haematology referral, testing and long-term monitoring in a haematology clinic. Venesection and medicines are provided through the hospital team. Some people pay privately for a second opinion or quicker testing, and ongoing care is often shared. Ask your team which risk category applies to you and how often you will be reviewed.