What can cause a travel thrombosis Long, immobile sitting, such
as in aircraft, restricts the flow of blood to the heart, which
active muscle movement promotes. This can result in deposits of
liquid, mostly in the lower leg. Increased pressure on the
tissues causes for its part a reduction of the blood
circulation. In rare cases, involving 'risk' persons, a blood
clot can develop on the wall of the vein. This is described as a
thrombosis, which impedes the flow of blood much more. In very
rare cases, part of the blood clot can break off and be carried
to the lungs by the flow of blood. By blocking a blood vessel
this can result in considerable reduction of the heart's pumping
performance. This is called an embolism of the lung, which in an
extreme situation can lead to sudden heart failure. Special risk
groups - People over 60 - Persons who have already suffered from
thrombosis - Overweight people - Pregnant women - People with a
malignant ailment - Women who take a contraceptive pill and also
smoke - People