Haematology - Royal Liverpool Hospital

 

What is Antithrombin?

This is the name given to one of the natural anticoagulants found in the blood.

Why is Antithrombin important?

If there is not enough antithrombin in the blood, or it does not work properly, then clots may be more likely to form in a vein causing deep vein thrombosis or pulmonary embolism. As far as we can tell the risk of clots forming in arteries, causing heart attack or strokes is not increased.

How do I become deficient in Antithrombin?

Usually by inheritance from your mother or father. Your doctor will exclude other causes

before deciding that you have an inherited deficiency. The diagnosis is definite if more

than one member of a family is shown to have low levels of antithrombin.

When is thrombosis likely to occur?

It can occur at any time although it is rare in childhood. The degree of risk increases with age.

What can I do to reduce my risk of developing a thrombosis?

Once your low level of antithrombin has been recognised it is important to try and modify your lifestyle to reduce your risk factors.

Factors which can increase the risk are:

  • Being overweight.
  • Smoking.
  • Prolonged immobilisation.
  • Having an operation.
  • Following an accident.
  • The combined oral contraceptive pill.
  • Pregnancy.
  • Hormone replacement therapy.
  • Severe illnesses such as cancer and chronic inflammation.
  • Presence of other inherited causes of a thrombotic tendency.

 

Pregnancy

Antithrombin deficiency is particularly associated with thrombotic tendency in pregnancy

and it is very important that you should consult your doctor as soon as possible if you are pregnant so that you can receive treatments with anticoagulants.

 

Having found out that I have antithrombin deficiency, what should I do?

The first thing to say is that you should not see yourself as ill or “abnormal”. Your

thrombotic tendency may not cause you any problems at all but you can take steps to

reduce the risk of thrombosis in the future by doing the following:

  • Lead a physically active life.
  • Eat a healthy diet and avoid being overweight.
  • Avoid smoking.
  • Avoid prolonged immobility during long journeys.
  • Take advice from your doctor if you are planning a long aeroplane flight (e.g., 8

hours).

  • Avoid certain types of contraceptive pill.
  • Take advice before starting hormone replacement therapy.
  • Liaising with your doctor if you are entering a high-risk period for thrombosis such

as major surgery, immobility, or pregnancy.

Under these circumstances your doctor will advise you about the need for specialist

hosiery or medication.

Should my family members be tested?

If it is likely that your antithrombin deficiency is inherited, then we would recommend that

your family members seriously consider undergoing testing. They can to this by visiting

their GP and asking for a referral to haematology for this.

 

Feedback

Your feedback is important to us and helps us influence care in the future. Following your discharge from hospital or attendance at your outpatient appointment you will receive a text asking if you would recommend our service to others. Please take the time to text back, you will not be charged for the text and can opt out at any point. Your co-operation is greatly appreciated.

 

Further information

Haematology Liverpool Patient Line

Tel: 0151 706 3397

Text phone number: 18001 0151 706 3397

External Websites www.thrombosisuk.org

 

Author: Haematology/Thrombosis CNS team

Review date: April 2029

PI 3040 V1