DVT is very difficult to spot, as the symptoms tend to be similar to a number of conditions.  Nevertheless, a type of ultrasound examination called a Doppler ultrasound, can show how fast the blood is flowing in a vessel, and can help to indicate whether a person may suffer from DVT. 

Symptoms may occur a few hours after travelling, or even days later, though the majority of people experience the above symptoms during the flight.

It is paramount to note, that many people naturally experience swelling of the ankles during a flight, which is not in any way associated with DVT.  

As you can see, it is often difficult to recognise the symptoms of DVT until the occurrence of a pulmonary embolism.

There may, however, be no symptoms at all until the pulmonary embolism occurs.  In the majority of cases, there is a pain in the calf with redness, swelling and tenderness.

It is important to note that DVT is distinguished from blood clots in superficial varicose veins in the legs, called phlebitis which is far less serious.

Click here for the symptoms of Deep Vein Thrombosis