Blood Disorders

Anaemia means there is too little haemoglobin, or too few healthy red blood cells, to carry oxygen efficiently. It is a finding, not a diagnosis in itself — the important question is always what is causing it.

• Iron deficiency, often from blood loss or from not absorbing enough iron.
• Vitamin B12 or folate deficiency.
• Blood loss — heavy periods, bleeding in the gut, surgery or injury.
• Long-term illness and inflammation (sometimes called anaemia of chronic disease).
• Kidney disease, because damaged kidneys make less of the hormone that tells the marrow to produce red cells.
• Inherited conditions such as sickle cell disease and thalassaemia.
• Bone-marrow problems that reduce production.
• Red cells breaking down too quickly (haemolysis).

Symptoms commonly include tiredness, breathlessness, paleness, dizziness, headaches and a fast heartbeat. Mild anaemia can cause very little at all.

This is the most common type of anaemia in the UK. Symptoms may include tiredness, breathlessness, paleness, brittle nails, hair thinning, headaches, restless legs, or a sore tongue.^{[3]NHS — iron deficiency anaemia}

The essential point is that the cause must be investigated, not just the level corrected. Iron deficiency in an adult can be the first sign of slow blood loss from the gut, so a GP will usually ask about bowel habit, stools, indigestion, periods, diet and previous surgery, and may arrange further tests or a referral.

Tiredness on its own is not a reason to start iron. Iron supplements taken without confirmed deficiency can cause side effects, can mask what is really happening, and can be harmful in some conditions such as thalassaemia or haemochromatosis. Treatment, dose and duration should be decided by a clinician, with a follow-up blood test to check it has worked.

B12 and folate are needed to make healthy red cells. Deficiency can follow a restricted diet, absorption problems, some medicines, gut surgery, coeliac disease, or an autoimmune condition called pernicious anaemia where the body cannot absorb B12 properly.^{[4]NHS — B12 or folate deficiency anaemia}

As well as the usual anaemia symptoms, B12 deficiency can affect the nervous system. Watch for:

• Pins and needles or numbness, often in the hands and feet.
• Unsteadiness, balance problems or changes to walking.
• Memory, concentration or mood changes.
• Vision changes, or a sore, smooth, red tongue.

Neurological symptoms need timely assessment, because delays in treatment can leave lasting problems. Do not self-treat with high-dose supplements before testing — taking folic acid when B12 is low can improve the blood count while nerve damage continues.

Sickle cell disease is an inherited condition affecting haemoglobin. Red cells can become stiff and sickle-shaped, block small blood vessels and break down early. It is most common in people of African and Caribbean family background, and also occurs in people of Middle Eastern, South Asian, Mediterranean and South American heritage.^{[5]NHS — sickle cell disease}

• Painful crises — episodes of severe pain, often in the back, chest, limbs or abdomen, sometimes triggered by cold, dehydration, infection, exertion or stress, and often with no trigger at all. Pain should be taken seriously and treated promptly.
• Increased infection risk, especially in young children, which is why preventive antibiotics and extra vaccinations are usually recommended.
• Long-term anaemia, tiredness and jaundice.
• Possible organ complications over time, including the chest, brain, kidneys, eyes, joints and spleen — which is why regular specialist review matters even when someone feels well.

Sickle cell trait is different. Someone with the trait has inherited one altered gene and one usual gene. They do not have sickle cell disease and are usually healthy, but they can pass the gene to a child. If both parents carry a haemoglobin gene change, there is a chance a child could inherit a condition, which is why screening and genetic counselling are offered.^{[11]NHS — sickle cell and thalassaemia screening}

Thalassaemia is a group of inherited conditions where the body makes less haemoglobin than usual. It is more common in people with Mediterranean, Middle Eastern, South Asian and South East Asian family backgrounds.^{[6]NHS — thalassaemia}

• Thalassaemia major and other severe forms usually need lifelong specialist care, regular blood transfusions for some people, and treatment to manage the iron that builds up as a result.
• Milder forms may cause mild anaemia that needs monitoring rather than transfusion.
• Thalassaemia trait (carrier) is not the same as having thalassaemia. Carriers are usually well, though they may have a mild anaemia picture on blood tests, and they can pass the gene on.

A common and important pitfall: the blood picture in thalassaemia trait can look like iron deficiency. Iron should not be taken unless deficiency has actually been confirmed, because unnecessary iron can be harmful in thalassaemia.

In haemolytic anaemia, red cells break down faster than the body can replace them. Causes include inherited red-cell conditions, autoimmune disease, some infections, some medicines and some inherited enzyme differences such as G6PD deficiency.

• Tiredness, breathlessness and paleness from the anaemia itself.
• Jaundice — yellowing of the skin or the whites of the eyes.
• Dark urine, sometimes described as tea- or cola-coloured.
• An enlarged spleen, sometimes felt as discomfort or fullness in the upper left abdomen.

Episodes can be set off by particular triggers, which differ between conditions and between individuals. Rather than publishing a general avoidance list — which can be wrong for your situation — ask your specialist team or pharmacist for the written guidance that applies to you, and check any new medicine, including over-the-counter products and herbal remedies, before taking it.

Platelets help blood clot. When the platelet count is low, or platelets do not work properly, bleeding takes longer to stop.

• Bruising easily, or large bruises from minor knocks.
• Pinpoint red or purple spots that do not fade under pressure.
• Nosebleeds, bleeding gums, or heavy periods.
• Prolonged bleeding after cuts, dental work or surgery.

Low platelets have many causes, including infection, pregnancy, medicines, liver disease, immune conditions, bone-marrow problems, and sometimes a laboratory artefact where platelets clump in the sample tube. One low result is not a diagnosis and often prompts a repeat test.

Immune thrombocytopenia (ITP) is one specific cause, where the immune system destroys platelets. It is diagnosed by a specialist after other causes have been considered — not from a single number on a printout. Some people with ITP need no treatment at all and are simply monitored.

These are inherited bleeding disorders where the blood does not clot normally because a clotting factor is missing, reduced or not working properly.^{[7]NHS — haemophilia[8]NHS — von Willebrand disease}

• Haemophilia A and B can cause bleeding into joints and muscles, which may show as pain, swelling, warmth, stiffness or reluctance to use a limb. Repeated joint bleeds can cause lasting damage, so prompt treatment matters.
• Von Willebrand disease is the most common inherited bleeding disorder and is often milder. It typically causes nosebleeds, bruising, heavy periods and prolonged bleeding after dental work, childbirth or surgery.
• Severity varies widely, including within the same family, and women and girls can be significantly affected.

Care is coordinated through specialist haemophilia centres. Everyone affected should have a personal treatment plan, know how to contact their centre at any hour, carry their treatment details, and tell dentists, surgeons, midwives and pharmacists about the condition before any procedure. Head injuries always need urgent assessment, even when the person feels fine.

Some inherited and acquired conditions make blood more likely to clot than usual. This is often called thrombophilia. Antiphospholipid syndrome is one acquired example.

Testing is not routine and is not offered to everyone who has had a clot. Results can be misleading if taken at the wrong time or while on anticoagulant treatment. A positive thrombophilia result does not automatically mean lifelong anticoagulation. Decisions depend on the type of clot, what triggered it, whether it has happened before, other health conditions, pregnancy plans and bleeding risk.

Detailed guidance on deep vein thrombosis, pulmonary embolism, stroke warning signs and anticoagulant treatment is on our dedicated page.

White cells can be too low, too high, or present in abnormal forms. Any of those can be temporary and harmless, or a sign of something that needs investigating.

• Neutropenia means a low count of neutrophils, the white cells that deal with bacterial infection. It can follow chemotherapy, some medicines, infections, autoimmune conditions or bone-marrow problems. Some people have a constitutionally lower count and are perfectly well.
• A raised white count is most often a response to infection, inflammation, smoking, stress, steroids or pregnancy — but a persistently high or unexplained count needs review.
• Abnormal-looking cells on a blood film may prompt further specialist tests.

If you are known to have neutropenia, or you are receiving chemotherapy, becoming unwell is urgent. Follow the emergency instructions your team has given you and use your 24-hour contact number rather than waiting to see how things go.

Bone marrow is the factory that makes blood cells. When production is reduced, red cells, white cells and platelets can all fall together, which may cause tiredness and breathlessness, repeated infections, and easy bruising or bleeding at the same time.

Aplastic anaemia is a rare condition where the marrow stops making enough cells. Causes include immune processes, some infections, some medicines and toxins, and sometimes no identified cause. Diagnosis needs specialist investigation, usually including a bone-marrow sample, and treatment may involve supportive transfusions, medicines that modify the immune system, or a stem-cell transplant.^{[36]The Aplastic Anaemia Trust}

These are conditions where the bone marrow does not work normally. They are usually managed by haematology teams and often over many years.

• Myeloproliferative neoplasms (MPNs) involve the marrow making too many of one or more blood cell types. Examples include polycythaemia vera (too many red cells), essential thrombocythaemia (too many platelets) and myelofibrosis (scarring of the marrow). Treatment aims to control the counts and reduce the risk of clots or bleeding.^{[20]NHS — polycythaemia}
• Myelodysplastic syndromes (MDS) involve the marrow producing cells that do not mature or work properly, leading to low counts. Some forms are mild and monitored; others need active treatment.^{[37]MDS UK Patient Support Group}

Both groups vary enormously in how they behave, so general internet descriptions are a poor guide to any individual’s situation. Ask your team what your specific subtype means for you.

Blood cancers affect the cells of the blood, bone marrow or lymphatic system. The three broad groups are:

• Leukaemia — cancer of the white cells and marrow, which may be acute (fast-developing) or chronic (slower).^{[14]NHS — AML}
• Lymphoma — cancer of the lymphatic system, divided into Hodgkin and non-Hodgkin lymphoma.^{[17]NHS — Hodgkin lymphoma}
• Myeloma — cancer of plasma cells in the bone marrow, which can affect bones, kidneys and blood counts.^{[19]NHS — myeloma}

Possible warning symptoms include persistent unexplained tiredness, repeated infections, unexplained fever, drenching night sweats, unexplained weight loss, swollen glands that do not settle, unusual bruising or bleeding, bone pain and persistent itching. These symptoms are far more often caused by something else — they are a reason to get checked, not evidence of cancer. A GP can arrange blood tests and, where appropriate, an urgent referral.^{[24]NICE NG12}

It is very common to be told a result is “slightly out of range” without anything being wrong. Blood counts shift with:

• Recent or current infection, and the weeks afterwards.
• Inflammation, injury or surgery.
• Pregnancy.
• Medicines, including steroids and some antibiotics.
• Hydration, exercise, smoking and time of day.
• Normal laboratory variation, sample handling, or platelets clumping in the tube.

Reference ranges are set so that a proportion of perfectly healthy people fall just outside them. That is why clinicians look at the pattern and the trend, may repeat the test after a few weeks, and may add other tests before deciding anything. Ask what the plan is and when the result will be rechecked.

Often the most important step. Treating heavy periods, a bleeding ulcer, coeliac disease, kidney disease, an infection or a medicine side effect can resolve the blood abnormality entirely. This is why finding the cause matters more than simply correcting a number.

Where deficiency is confirmed, replacement may be given as tablets, liquid, injections or, occasionally, an infusion in hospital. Follow-up blood tests check that levels have improved and stayed improved. Side effects such as constipation or stomach upset are common with iron and can often be managed by changing the preparation or how it is taken — ask a pharmacist rather than simply stopping.

Transfusions of red cells, platelets or plasma products may be used for severe anaemia, active bleeding, some inherited conditions and during some treatments. They are given when the benefit clearly outweighs the risks, and often alongside treatment of the underlying cause.^{[26]NICE NG24}

Some conditions, particularly anaemia related to kidney disease, may be treated with medicines that stimulate the marrow to make more red cells. Others may involve medicines that raise platelet counts or support white-cell recovery after chemotherapy. These need careful monitoring and specialist supervision.

Where the immune system is destroying blood cells — as in immune thrombocytopenia, autoimmune haemolytic anaemia or aplastic anaemia — treatment may involve steroids, immunoglobulin or other immune-modifying medicines. These can increase infection risk, so people are usually given specific advice about what to watch for and who to call.

Care for sickle cell disease and thalassaemia is delivered by specialist centres and may include preventive antibiotics, extra vaccinations, medicines to reduce complications such as hydroxycarbamide, regular or occasional transfusions, treatment to remove excess iron, pain plans, and, for some people, stem-cell transplant or newer gene-based therapies where they are available and appropriate.^[5]NHS

Where the risk is clotting rather than bleeding, anticoagulant medicines may be prescribed, sometimes for a set period and sometimes long term. They require monitoring, care around procedures and dental work, and awareness of bleeding signs. Full detail is on our clots page.

People with haemophilia or von Willebrand disease may receive clotting factor or other specific treatments, either regularly to prevent bleeds or at the time of a bleed, injury or procedure. Many people or their families are trained to give treatment at home as part of an agreed plan, with the specialist centre available around the clock.^{[31]The Haemophilia Society}

For blood cancers and some forms of marrow failure, treatment may include chemotherapy, targeted or immune-based therapies, radiotherapy, or a stem-cell (bone marrow) transplant. Some slow-growing conditions are actively monitored without treatment at first, which can feel counter-intuitive but is often the safest approach.^{[13]NHS — stem cell transplants}

Monitoring is part of treatment, not an optional extra. It shows whether treatment is working, catches side effects early, and picks up changes before they cause symptoms. Keep appointments even when you feel well, and ask for copies of your results so you can keep your own record.

Living with a long-term blood condition can bring pain, fatigue, uncertainty, time off work and repeated hospital visits. Specialist nurses, clinical psychology services, condition-specific support lines and peer groups all exist for good reason. Asking for that support is part of good care.

Fatigue from a blood condition is not ordinary tiredness and does not always improve with rest. Pacing — breaking activity into manageable pieces, planning the demanding tasks for your better hours, and stopping before you hit the wall — usually works better than pushing through and crashing. Tell your team if fatigue is worsening, because it may be treatable.

People who get recurrent pain, especially with sickle cell disease, should have a written personal pain plan agreed with their team, setting out what to take at home, when to escalate, and where to go for treatment. Take a copy with you to A&E — it helps staff act quickly and reduces the risk of your pain being underestimated.

Handwashing, food hygiene, dental care and avoiding contact with people who are clearly unwell all help, particularly for people with low white cells or without a working spleen. Some people are advised to take preventive antibiotics. Know the signs of infection you must not ignore, and keep the emergency number somewhere you can find it at 3am.

Some people with blood disorders, no functioning spleen, or reduced immunity are offered additional vaccinations and annual flu vaccination. What is recommended depends on the condition and the treatment, so follow the advice given by your own clinical team rather than general guidance.^{[23]NHS — vaccinations}

Staying well hydrated, keeping warm, avoiding sudden temperature changes, treating infections early, pacing strenuous exercise and managing stress can all reduce the chance of a painful crisis. Triggers vary between individuals, so learning your own pattern is worth more than any general list.

Tell your dentist about your blood disorder and medicines before any treatment, including cleaning and extractions. People with bleeding disorders or low platelets may need planning with their specialist centre first. Good routine dental care reduces the need for procedures later, and some people qualify for help with NHS dental costs.

Plan ahead: carry a letter from your team, take enough medicine plus extra in hand luggage with original labels, know where the nearest specialist unit is, and check vaccination and altitude advice with your team. Declare your condition honestly to insurers — non-disclosure invalidates cover. Specialist insurers often quote more sensibly than mainstream comparison sites for long-term conditions.

An alert card, wallet card or app entry stating your diagnosis, treatment, allergies, anticoagulant use and specialist contact number can shape the first ten minutes of emergency care. Medical alert jewellery is a personal choice, but it speaks for you when you cannot. Add emergency contacts to your phone’s lock-screen medical information as well.

Many people work full-time with a blood disorder. Adjustments such as flexible hours around infusions, rest breaks, a parking space, working from home during recovery periods, or a phased return after treatment can make the difference between coping and giving up work.

Anxiety about results, frustration at fatigue, and the strain of repeated appointments are all common and worth raising. Conditions and treatments can also affect fertility, periods, sexual function and contraception choices — these are legitimate clinical topics, and specialist teams discuss them routinely. Ask; you will not be the first.

A balanced diet supports general health, and specific deficiencies should be corrected on advice. Be sceptical of “blood-building” foods, detoxes and supplements marketed at people with blood conditions — there is no food that replaces treatment, and some supplements interfere with medicines. Exercise is usually good for you, but the right type and intensity depends on your condition, your blood counts and your joints, so agree it with your team.