Deep Vein Thrombosis (DVT) is a well documented obstructive thrombotic disease and is part of the wider group of thromboembolic disorders which represent the third most common cause of cardiovascular death after heart attacks and stroke. Typically, a clot forms in the lower limb, during which pain and swelling are classical symptoms, and if treatment is delayed, can result in fragmentation of the clot which can result in a clot in the lung (Pulmonary Embolism, PE) and/or the brain (Stroke, CVA), both of which can have fatal outcomes. Early diagnosis and prompt treatment can reduce the morbidity and improve patient outcomes.

There are individuals in which developing a DVT can be more likely, including patients who have had a recent surgery or those with certain conditions, such as cardiac diseases or cancer as well as those with reduced mobility. It can also be influenced by certain medications, such as patients on high doses of steroids, HRT, or the oral contraceptive.

It is also known that long-haul air travel increases the risk of a DVT in travellers, and airlines routinely provide travel advice on how to try and reduce the risk of developing a DVT during air travel. There are several factors which increase the risk in air travel, such as the seat type and space, as being cramped results in reducing the venous blood flow in the legs and causes venous stasis, and factors of being in a pressurised cabin also have an effect, such as dehydration or the physiological effects of altitude on blood flow around the body.

Statistics and Impact 

The statistics surrounding DVT are significant:

  • Global Incidence: Approximately 1-2 in 1,000 people are affected by a DVT each year.
  • Travel-Related DVT: For healthy travellers, the risk of developing a DVT on long-haul flights (lasting more than four hours) is about 1 in 4,656 flights, but for flights lasting more than 16 hours, this increases to 1 in 1,200.
  • Complications: It is estimated between 23-60% of individuals with a DVT may develop post-thrombotic syndrome within 2 years which can cause long-term pain and swelling.

Assessing the risk 

Whether a patient is travelling alone after discharge from hospital, or whether they are being escorted by a medical practitioner, it is important to evaluate the risk of developing a DVT and to determine the most appropriate means to reduce the risk.

1. Risk Assessment and Preventive Measures (Patients) 

Before travel, we conduct a thorough medical assessment of the patient’s history and condition, including:

  • Medical history (e.g. cancer, heart or clotting diseases)
  • Recent illness
  • Current and chronic medications
  • Physical condition and mobility/restrictions
  • The flight duration, number of sectors, layovers, and class of travel

If we determine a patient to be at an increased risk of developing a DVT, we may apply risk-reduction strategies, such as:

  • Flight schedule: We may look for a different schedule or suggest a different class of travel
  • Compression Stockings: We may advise wearing graduated compression stockings during flights to improve blood flow.
  • Hydration and Movement: We will educate patients and advise regular hydration and periodic movement or leg exercises during long flights.
  • Medication: We may consider supplemental medication to reduce the likelihood of thrombus development, such as Low Molecular Weight Heparin

2. Risk Assessment and Preventive Measures (Medical escorts) 

We have a duty of care to our medical escorts who are supporting patients during a medical repatriation. Part of this is a regular health review with the medical escorts to ensure that any conditions that may significantly increase the risk are well understood.

Before undertaking a medical repatriation mission, we consider several points to risk—reduce the risk of developing a DVT during their travel, including:

  • The flight duration to reach the patient
  • The class of travel on all sectors
  • The amount of ground time in the patient’s location
  • The amount of rest time in the destination country after the mission is complete

Patients and medical escorts who present with an increased DVT risk are evaluated by MedResQ doctors who will decide whether any adjustments or additional medication are needed to reduce the risk of developing a DVT.

3. Management of medically escorted patients  

During medically escorted repatriations, our medical escorts will assess and manage patients in the following ways:

  • Patients undergo a through physical assessment pre-flight by the medical practitioner
  • Routine in-flight assessments are performed, including assessment of the lower limbs and haemodynamic data recordings are taken
  • Medication can be administered before and/or during travel
  • Thorough documentation of any findings, the management or treatment administered

4. Training and education for staff 

We provide ongoing training for our staff to stay current with best practices in DVT prevention and management. This training includes:

  • Recognizing risk factors and symptoms of DVT
  • Administering in-flight care and emergency interventions
  • Understanding the latest guidelines for anticoagulant therapy and other treatments


Deep Vein Thrombosis is a significant medical condition that poses risks during air travel, particularly on long-haul flights. As an international medical assistance company, we are committed to understanding and reducing these risks through comprehensive risk assessments, preventive measures and vigilant in-flight monitoring for medically escorted patients. By staying informed and prepared, we aim to ensure the safety and well-being of our clients, providing peace of mind as they travel around the world.