Thrombophilia
Thrombophilia is an increased tendency of the blood to form clots. The word sounds like a verdict, but it describes not a disease so much as a trait: all…
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Medicines commonly prescribed for Thrombophilia
For informational purposes only. Always consult a doctor before using any medicine.
Dosage form: INJECTABLE, 2,000 IU (20 mg)/0.2 mlActive substance: enoxaparinManufacturer: Techdow Pharma Netherlands B.V.Prescription requiredDosage form: TABLET, 20 mgActive substance: rivaroxabanManufacturer: Laboratorios Normon S.A.Prescription requiredDosage form: TABLET, 20 mgActive substance: rivaroxabanManufacturer: Tecnimede España Industria Farmaceutica S.A.Prescription required
Thrombophilia is an increased tendency of the blood to form clots. The word sounds like a verdict, but it describes not a disease so much as a trait: all else being equal, a clot forms a little more readily in this person than in the next. Most people who have it go through life without a single thrombosis and without a single tablet. It becomes dangerous not on its own but in particular circumstances — an operation, a long spell of immobility, pregnancy, hormonal treatment. So a conversation about thrombophilia is almost always a conversation not about treatment but about what to do during exactly those periods.
A tendency, not an illness
Clotting works like a pair of scales: some proteins push the blood towards clotting and others hold it back. When the pan tips towards clotting, the result is thrombophilia. The causes fall into two large groups.
Inherited — you are born with it. The commonest in people of European descent is the factor V mutation known as factor V Leiden: a few people in every hundred carry it, and the great majority neither know nor need to. The prothrombin mutation works in much the same way. Less common is a shortage of the natural anticoagulants — antithrombin, protein C, protein S — which are rare but carry a higher risk.
Acquired — it develops during life. This group includes antiphospholipid syndrome, cancer, bone marrow disorders that thicken the blood, nephrotic syndrome in kidney disease, severe liver disease and inflammatory bowel disease.
Here is the thing that matters most. Carrying a mutation is not a diagnosis and on its own calls for neither treatment nor restrictions. Most carriers never have a single thrombosis in their lives. The risk quoted on laboratory reports is a relative figure: "three times higher" sounds alarming, but if the starting probability is small, three times small is still small. Thrombophilia does not act alone; it shows itself when something else is added to it.
When the risk genuinely rises
These are the circumstances that make knowing about your thrombophilia worthwhile at all. In these periods the risks add up, and this is when measures are needed.
- An operation, especially on joints, in the abdomen or in the pelvis, and in general any procedure under anaesthetic followed by bed rest.
- Immobility: a plaster cast on the leg, an injury, a serious illness with bed rest, a hospital admission.
- Long journeys — a flight or a trip of more than a few hours with no chance to get up and move about.
- Pregnancy, and above all the first weeks after the birth, which carry the highest risk of the whole episode.
- Combined hormonal contraceptives and oestrogen hormone replacement therapy.
- Cancer and its treatment — the tumour itself markedly increases clotting and chemotherapy adds to it.
- Severe infection, dehydration, marked excess weight, smoking, a venous catheter and age.
From that comes a simple practical rule: if you know you have a thrombophilia, tell the doctor in advance — before planned surgery, when a cast is being applied, when planning a pregnancy, when choosing contraception. Beforehand, not afterwards. Whether you are given preventive treatment for those days depends on it.
The test is not for everyone
Thrombophilia testing is not something to request "just in case" or because a laboratory offers it. It is arranged when the result could change something, and that is the doctor's decision.
It is considered when the thrombosis happened at a young age or with no obvious cause, when clots keep recurring, when a clot has formed in an unusual place — the veins of the abdomen or the brain, for instance — when several close relatives had clots when young, and after repeated pregnancy losses. Even then the result more often refines the picture than changes the treatment: how long anticoagulants are taken after a clot is decided above all by the circumstances of the episode itself, not by the mutation found.
Why the timing of the test matters
With this test, timing counts for more than with most. During the acute phase of a thrombosis and while anticoagulants are being taken, the results are often unreliable, and in both directions.
- During a fresh clot the natural anticoagulants are used up and their levels look falsely low.
- Warfarin lowers protein C and protein S, so measuring them on it is pointless.
- Heparin distorts the antithrombin assay.
- Direct oral anticoagulants interfere with lupus anticoagulant testing and give false results.
- Pregnancy and oestrogen-containing contraceptives lower protein S physiologically.
The test is therefore usually done no sooner than several months after the episode, and after a break in anticoagulation if such a break is safe. Stopping treatment on your own in order to have a blood test is not on. The genetic tests — for factor V Leiden and the prothrombin mutation — do not depend on timing or medicines and can be done at any point, though on their own they settle very little either.
Antiphospholipid syndrome is a separate story
It is often listed alongside the inherited mutations, which is misleading. Antiphospholipid syndrome works differently: it is an acquired autoimmune condition in which the body makes antibodies against its own proteins bound to cell membranes. It is managed differently, so it is important not to lump it in with the rest.
There are three differences, and all of them count.
- It causes arterial as well as venous clots — including stroke in a young person with no risk factors.
- It is closely tied to complications of pregnancy: repeated early miscarriage, later fetal death, severe pre-eclampsia, poor fetal growth.
- It needs different treatment. Direct oral anticoagulants are unsuitable in a number of these cases, and warfarin with clotting monitoring is used instead. In pregnancy, low-dose aspirin and low molecular weight heparin are prescribed, and that improves outcomes appreciably.
One more feature: the diagnosis is not made on a single test. The antibodies can appear briefly after infections and mean nothing at all, so a positive result must be repeated no sooner than twelve weeks later. Antiphospholipid antibodies found once, with no clots and no pregnancy losses, are not a diagnosis and not a reason to start treatment. Antiphospholipid syndrome often goes with systemic lupus erythematosus, so such patients are usually looked after by a rheumatologist together with a haematologist.
Pregnancy, birth and contraception
Pregnancy itself increases clotting — that is how the body prepares for labour and blood loss. The highest risk falls not on the pregnancy but on the first weeks after delivery. If thrombophilia, a previous clot or clots in close relatives are added to that, the doctor will weigh up preventive treatment with low molecular weight heparin: during the pregnancy, after the birth, or both. Those medicines do not cross the placenta and are compatible with breastfeeding.
Contraception is a separate and very practical question. Combined preparations containing oestrogen raise the risk of clots in any woman, and in a woman who carries a thrombophilia those risks multiply together. That is exactly where knowing about the thrombophilia genuinely changes the decision: oestrogen-free methods are usually chosen — progestogen-only preparations, an intrauterine system, non-hormonal options. If there have been clots in the family at a young age, say so before starting the pill rather than after.
About pregnancy loss it is worth being straight: the link between inherited mutations and miscarriage is weaker than is generally assumed, and prescribing anticoagulants routinely in ordinary recurrent miscarriage has not been shown to help. The exception is antiphospholipid syndrome, where treatment really does work.
When to act immediately
This is the part of the page to remember above all. Thrombophilia itself does not hurt and gives no sign of itself; what matters are the clots, and their signs need recognising at once.
Deep vein thrombosis in the leg — see a doctor the same day if you develop:
- swelling of one leg, most often the calf, while the other leg is its usual size;
- a bursting pain or heaviness in the calf that is worse on walking and standing;
- redness or a bluish tinge to the skin, and warmth to the touch;
- a tight, tender calf on pressing.
Pulmonary embolism — call an ambulance immediately if you develop:
- sudden breathlessness, short of air even at rest;
- chest pain that is worse on breathing in deeply and on coughing;
- coughing up blood;
- a very fast heartbeat, cold sweat, a sense that something is badly wrong;
- a blackout or the feeling that you are about to faint.
In Spain, Italy, Portugal, Poland and Ukraine the single European number 112 is in use. Do not drive yourself and do not try to make your own way there. In antiphospholipid syndrome the signs of a stroke join this list — sudden weakness of the arm and leg on one side, a drooping face, trouble speaking or seeing. That too means calling an ambulance without delay.
What you can do yourself
Thrombophilia without clots does not usually call for ongoing treatment, and there is no need to "thin the blood" preventively for years. But some things are in your hands.
- Keep moving when travelling: get up and walk about every hour or two, and work your feet and ankles while seated. Drink water and go easy on alcohol, because dehydration thickens the blood.
- Compression stockings on a long journey or after an operation are useful, but the compression class and the size are best chosen with a doctor or pharmacist rather than guessed at.
- After an operation or injury, start moving as early as your doctor allows: early mobilisation cuts the risk far more than any supplement.
- Stop smoking, keep an eye on your weight, keep up regular physical activity.
- Carry details of your diagnosis and your medicines with you — it matters in an emergency admission.
- If you take anticoagulants, do not miss doses and do not stop them on your own, and warn the doctor in advance before any procedure, dental work included.
Relatives of a carrier do not need testing across the board. But it is useful for them to know about the family trait so they can mention it before an operation, in pregnancy and when choosing contraception.
Online consultation
People usually come to this subject holding a laboratory report and asking one question: how bad is it. At a remote appointment the doctor will help you read that report, explain what the mutation found means in your particular situation and, just as importantly, what it does not mean. Very often the conversation ends with no treatment being needed at all — what is needed is a plan for a handful of specific situations.
The second reason to get in touch is to plan the investigation properly: whether it is needed at all, which items make sense and which do not, and when to have the blood taken so that the result is trustworthy rather than skewed by medicines. The third is preparing for the events all of this is about in the first place: planned surgery, pregnancy, a long flight, the choice of contraception.
If, however, one calf has swollen and become painful, and all the more so with breathlessness, chest pain on breathing in or coughing up blood, there is no waiting for an appointment: that needs emergency care.
This material is for information only and does not replace medical advice.
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