Blood disorders
Anaemia, a low platelet count, bleeding and clots are blood disorders. Many abnormal blood test results have a cause other than cancer, but the cause must be found. Here you can read what is checked and when to get urgent help.
What is a blood disorder?
Blood has three main groups of cells: red blood cells, which carry oxygen around the body, white blood cells, which protect against infection, and platelets, which help the blood clot. Blood disorders mean a problem in one of these cells or in the fluid and proteins that make blood clot.
The most common ones:
- Anaemia. The red cells or haemoglobin are low. The causes are many: iron-deficiency anaemia, deficiency of vitamins such as B12 and folate, a long-term illness (such as kidney trouble or inflammation), a bone marrow problem, early destruction of red cells and inherited diseases.
- Low platelets (thrombocytopenia). The bone marrow may make too few, the platelets may be destroyed too much, or the immune system may attack them (as in ITP). Some medicines can lower platelets too.
- Bleeding disorders. Such as haemophilia and von Willebrand disease, or a problem with platelet function.
- Clots. Sometimes the blood clots too much, and a clot forms in the leg veins (deep vein thrombosis) or the lung (pulmonary embolism). Cancer, surgery, long periods without moving, hormone medicines containing oestrogen and having a catheter are risk factors.
An abnormal result does not always mean cancer
When a blood test shows an abnormal number, the first thought of many patients is cancer. Know that the blood count depends on many factors: infection, dehydration, iron deficiency, medicines, periods and so on. An abnormal test result alone is not a definite sign of cancer, and the doctor weighs it alongside symptoms, examination and sometimes a repeat test or a biopsy.
Even so, we cannot say the problem is always simple. A number that stays abnormal on a repeat test, or comes with symptoms such as fever, night sweats, severe tiredness or weight loss for no reason, needs a closer look. This is done by a blood specialist.
Who should be seen?
- Someone whose blood test (complete blood count) is abnormal and whose family doctor has said to see a blood specialist
- Someone with symptoms of anaemia: weakness, shortness of breath, dizziness, a fast or irregular heartbeat, cold hands and feet, paleness, headache
- Someone with easy bruising, gum bleeding, nose bleeding for no reason, tiny red spots on the skin, very heavy periods or long bleeding after a cut or dental work
- Someone who has had a clot before. Sudden pain and swelling in one leg or arm should not wait for an appointment; see the section “When should you get urgent help?”
- Someone with an enlarged lymph node. A lymph node usually swells because of infection and settles within one to two weeks. If it is getting bigger, is hard and does not move, stays more than a week or comes with fever and night sweats, show it to a doctor. It is rare for the cause to be a blood cancer or lymphoma.
- Someone with a family history of a bleeding disorder or clots
How is it investigated?
- History and examination. Symptoms, medicines, family history, periods and diet.
- Complete blood count (CBC). Measures the number and size of the red cells, white cells and platelets.
- Blood film. The blood sample is looked at under a microscope.
- Specific tests. Depending on the suspicion, such as iron, vitamin B12 and folate, clotting tests and others.
- Finding the cause. For iron-deficiency anaemia, bleeding is the most common cause. Sometimes a check of the digestive tract or of menstrual bleeding is needed.
- Bone marrow biopsy. Needed in some patients, for example when a bone marrow problem is suspected. It is done under local anaesthetic and is usually in an outpatient clinic.
How is it treated?
Treatment depends entirely on the cause.
- Iron deficiency. First the cause is found (for example bleeding). Iron tablets are taken as your doctor advises and usually for several months. Side effects such as constipation or dark stools may occur. Keep iron tablets out of the reach of children, because taking too many is dangerous for a child.
- Vitamin deficiency. A change of diet or a supplement, as your doctor advises.
- Long-term illness. Treating the underlying illness usually improves the anaemia.
- Bone marrow problem. Treatment is specialised and sometimes includes medicines, blood transfusion and, in some patients, a transplant.
- Low platelets. Depends on the cause. Sometimes no treatment is needed. If a medicine is the cause, it is changed (only on your doctor’s advice). If the immune system is the cause, medicines that suppress the immune system or raise platelet production are used.
- Bleeding disorder. Such as haemophilia, treated with clotting factor infusions. In von Willebrand disease, people should not take aspirin or ibuprofen without a doctor’s opinion.
- Clots. Almost all patients are treated with blood-thinning medicines so the clot does not grow and no new clot forms. In special situations there are other methods. Only the doctor decides the type and length of medicine. Do not stop a blood thinner on your own.
What can you do yourself?
- Carry a list of all your medicines, supplements and herbs
- Do not take aspirin, ibuprofen or similar medicines without your doctor’s opinion, especially if your platelets are low or you have a bleeding problem
- Before surgery, dental work or childbirth, tell the doctor that you have a clotting or bleeding problem
- If there is a family history of bleeding or clots, say so
- Keep your test results and their dates so the trend can be seen
When should you get urgent help?
- Bleeding that does not stop with firm pressure: call 115 (the emergency number inside Iran).
- Sudden shortness of breath, new or severe chest pain, sharp or pressing, a fast heartbeat or coughing up blood: call 115. A clot may have gone to the lung.
- Swelling, pain and warmth in one leg or arm: see a doctor or the emergency department at once.
- Black or bloody stool, severe headache or confusion: call 115 or go to the emergency department. Red urine: tell a doctor right now.
- New tiny red or purple spots on the skin, a lot of bruising for no reason or bleeding gums, especially with fever or weakness: go to a doctor or the emergency department right now to have a blood test.
- Fainting, or chest pain with signs of anaemia: go to the emergency department at once.
- If you are having chemotherapy and have a fever of 38 degrees or higher: this is an emergency. See the page “When should I call for urgent help?”
Diagnosis and treatment are decided by the doctor after examining you and seeing your records. This page is general guidance.
Frequently asked questions
My blood test is abnormal. Does that mean I have cancer?
Not necessarily. An abnormal blood test result alone is not a definite sign of cancer. Diet, activity, medicines, periods and dehydration also affect the blood count. But it cannot be concluded from this that there is no problem either. The doctor has to find the cause, taking account of symptoms and sometimes a repeat test.
Is anaemia always cured with iron tablets?
No. Anaemia has different causes: iron deficiency, vitamin deficiency, a long-term illness, a bone marrow problem and others. In iron deficiency, finding the site of bleeding or the cause of the deficiency matters more than the tablet itself. Do not start iron tablets without a check-up and your doctor's opinion.
Does a low platelet count mean I will bleed?
A mildly low platelet count often has no symptoms. When it falls lower, bruising, nose or gum bleeding, tiny red spots on the skin or heavy periods may occur. The cause and treatment differ depending on the type of problem.
Are there inherited blood diseases?
Yes. Some bleeding disorders such as haemophilia and von Willebrand disease are inherited, and so are some anaemias. If there has been a lot of bleeding or clotting in your family, say so at the visit.
What should I do if I have a clot in my leg?
Take pain, swelling, tenderness and warmth in one leg or arm seriously and see a doctor at once. If sudden shortness of breath or chest pain comes with it, call 115 (the emergency number inside Iran).