Thrombophilia means blood has an increased tendency to form clots. Most people with thrombophilia don't have symptoms. Symptoms only occur if thrombophilia causes a blood clot. See your GP immediately if you have any combination of symptoms in symptoms section below. Dial 999 for an ambulance if symptoms are severe.
How thrombophilia affects blood clotting
If you have thrombophilia, you have an imbalance (too much or too little) in proteins in the blood known as clotting factors. These control the formation of a blood clot.
Symptoms of thrombophilia
Most people with thrombophilia don't have symptoms and never have health problems. Symptoms only occur if thrombophilia causes a blood clot.
If you have thrombophilia, you're more likely to develop a blood clot in one of the large veins in your leg (deep vein thrombosis) or a pulmonary embolism, where the blood clot breaks off, travels in the circulation and lodges in the arteries supplying the lungs.
Warning signs of DVT include:
- pain, swelling and tenderness in your leg (usually in your calf)
- a heavy ache in the affected area
- warm skin in the area of the clot
- red skin, particularly at the back of your leg below the knee
DVT usually only affects one leg, though not always. The pain may be worse when you bend your foot up towards your knee.
Part of the blood clot can sometimes break away and travel through the bloodstream. This can be dangerous because the clot becomes lodged in the lungs.
Known as a pulmonary embolism, this serious and potentially life-threatening condition can prevent blood reaching your lungs.
The symptoms of a pulmonary embolism are:
- chest or upper back pain
- shortness of breath
- coughing – usually dry, but you may cough up blood or mucus containing blood
- lightheadedness or dizziness
See your GP immediately if you have any combination of the above symptoms. You can also contact GP out of hours service for advice.
Dial 999 for an ambulance if your symptoms are severe.
If you develop a blood clot, you may be tested for thrombophilia a few weeks or months later. A blood sample is taken to look for chemical imbalances.
You may be referred to a specialist in diagnosing and treating blood disorders (a haematologist) if the blood test results suggest you have thrombophilia.
Types of thrombophilia
There are many different types of thrombophilia. Some types are inherited, while other types develop later in life. The main types of thrombophilia include:
- Factor V Leiden (H3)
- prothrombin 20210
- protein C, protein S and antithrombin deficiency
- antiphospholipid syndrome
Read more about the main types of thrombolia on the NHS website:
Many people with thrombophilia won't need treatment. You'll only need treatment if you develop a blood clot or you're at risk of developing a clot.
This will depend on the type of thrombophilia you have and factors such as your age, weight, lifestyle and family history. If you have been diagnosed with thrombophilia, the healthcare professional managing your care will discuss with you the most appropriate treatment options.
If you have thrombophilia, you need to be aware of the symptoms of a blood clot and see your GP immediately if you think you have one.
You should also take the following precautions to lower your risk of developing blood clots:
- lose weight if you're overweight
- stop smoking
- eat a healthy, balanced diet and exercise regularly
- avoid being immobile for long periods – being inactive can cause a DVT
If you're pregnant or planning to get pregnant, discuss this with your GP and tell your midwife and obstetrician about your condition.
You may need to take medication while you're pregnant to prevent problems occurring during pregnancy or miscarriage.
If you're having a major operation, make sure you tell the healthcare professionals treating you about your condition.
Women with thrombophilia shouldn't take the combined oral contraceptive pill or hormone replacement therapy (HRT) because it further increases the risk of developing a blood clot.
Blood clot risk
Anyone can get a blood clot, but you're most at risk if you've been unwell for long periods and unable to move around much.
Blood clots may be linked to long plane journeys or the contraceptive pill, but you're much more likely to have one after going into hospital.
About two-thirds of all blood clots occur during or just after a hospital stay.
More useful links
The information on this page has been adapted from original content from the NHS website.
For further information see terms and conditions.