NICE clinical guidelines
Issued: January 2010 (last modified: June 2015)

Venous thromboembolism in adults admitted to hospital: reducing the risk

This is an extract from the guidance. The complete guidance is available at


Recommendations on mechanical prophylaxis for venous thromboembolism in patients who are admitted for stroke have been added to section 1.4. The addendum contains details of the methods and evidence used to update these recommendations.

The House of Commons Health Committee[1] reported in 2005 that an estimated 25,000 people in the UK die from preventable hospital‑acquired venous thromboembolism (VTE) every year. This includes patients admitted to hospital for medical care and surgery. The inconsistent use of prophylactic measures for VTE in hospital patients has been widely reported. A UK survey suggested that 71% of patients assessed to be at medium or high risk of developing deep vein thrombosis did not receive any form of mechanical or pharmacological VTE prophylaxis[2].

VTE is a condition in which a blood clot (thrombus) forms in a vein. It most commonly occurs in the deep veins of the legs; this is called deep vein thrombosis. The thrombus may dislodge from its site of origin to travel in the blood – a phenomenon called embolism.

VTE encompasses a range of clinical presentations. Venous thrombosis is often asymptomatic; less frequently it causes pain and swelling in the leg. Part or all of the thrombus can come free and travel to the lung as a potentially fatal pulmonary embolism. Symptomatic venous thrombosis carries a considerable burden of morbidity, including long‑term morbidity because of chronic venous insufficiency. This in turn can cause venous ulceration and development of a post‑thrombotic limb (characterised by chronic pain, swelling and skin changes).

VTE is an important cause of death in hospital patients, and treatment of non‑fatal symptomatic VTE and related long‑term morbidities is associated with considerable cost to the health service.

The risk of developing VTE depends on the condition and/or procedure for which the patient is admitted and on any predisposing risk factors (such as age, obesity and concomitant conditions).

This guideline makes recommendations on assessing and reducing the risk of VTE in patients in hospital. It offers guidance on the most clinically and cost‑effective measures for VTE prophylaxis in these patients. The recommendations take into account the potential risks of the various options for prophylaxis and patient preferences.

The guideline assumes that prescribers will use a medicine's summary of product characteristics to inform decisions made with individual patients.

Recommendations about medicines

The guideline will assume that prescribers will use a medicine's summary of product characteristics to inform decisions made with individual patients.

This guideline recommends some medicines for indications for which they do not have a UK marketing authorisation at the date of publication, if there is good evidence to support that use. The prescriber should follow relevant professional guidance, taking full responsibility for the decision. The patient (or those with authority to give consent on their behalf) should provide informed consent, which should be documented. See the General Medical Council's Good practice in prescribing and managing medicines and devices for further information. Where recommendations have been made for the use of medicines outside their licensed indications ('off‑label use'), these medicines are marked with a footnote in the recommendations.

[1] House of Commons Health Committee (2005) The prevention of venous thromboembolism in hospitalised patients. London: The Stationery Office.

[2] Rashid ST, Thursz MR, Razvi NA et al. (2005) Venous thromboprophylaxis in UK medical inpatients. Journal of the Royal Society of Medicine 98 (11): 507–12.