Deep Vein Thrombosis
Deep Vein Thrombosis – What is it?
DVT, or Deep Vein Thrombosis, is a condition
whereby clotting of a deep vein occurs - normally due to the slowing
down, or stopping, of the blood flow through that vein. In travellers
this normally occurs in the leg, but clots can form in other parts
of the body also.
Generally speaking, there are two types of vein
– superficial and deep. Superficial veins are veins that
run close to the surface of the skin and while clotting can form
in these veins it is not considered as dangerous. Deep veins,
on the other hand, are veins that run close to the centre of the
limb and are surrounded by muscle and other tissue. It is these
veins where DVT’s are more likely to form and have the potential
to cause fatal injury.
Although a link between DVT and long-haul flying has been acknowledged
since the 1950’s, it is only in recent times that travellers,
mostly because of the press coverage, are becoming aware of the
inherent dangers of prolonged, cramped, flying conditions. Indeed,
DVT is not just limited to flying, but in all cases of prolonged
immobility there is an inherent risk of a DVT forming. Equally,
DVT is not limited just to passengers in economy class even though
the condition has been tagged 'economy class syndrome'. There
have been reported fatalities of DVT with passengers flying business
and first-class also as well as instances of the illness striking
people travelling in other modes than on an airline.
Who is at risk of getting Deep Vein Thrombosis?
There have been many studies, particularly of
late, into the numbers of people who suffer DVT while flying on
long-haul flights. The statistics vary depending on the study
so accurate figures are not really known, and the specific causes
are equally unknown. Whether the figures of those who might develop
DVT are 1 in 100, or 1 in 1,000,000 is largely irrespective. Some
studies have even suggested that up to 1 in 30 passengers on long-haul
flights will develop DVT. What is important to know is that it
can happen, and it does happen. In fact, while the studies have
not been able to totally agree on the numbers of people affected,
they do generally agree on those who fall into the high-risk category
for developing DVT. High-risk criteria for developing DVT are
This is not to say that people who fall under
this list of criteria will definitely develop DVT while flying,
just that they are a higher risk than normal and should take precautionary
measures where possible. It should also be noted that people who
do not fit the criteria above may also develop DVT but their chances
of doing so are much slimmer. In general though, the vast majority
of people who fly long haul needn’t be too concerned about
developing DVT as long as they are able to take reasonable precautions
and exercise their limbs every so often.
- Have a medical history of blood clotting or a family history
of blood clotting
- Are over 40 years of age
- Pregnant women (or those who have recently given birth)
- Women who are on hormonal medication (or taking contraceptive
- Have (or have had) medical conditions such as heart or circulation
problems or blood diseases
- Have undergone recent medical surgery or treatment
- Have suffered a stroke
- Are reasonably tall or short (due only to their seating
- Are obese – anecdotal evidence only
- Chronic smokers – anecdotal evidence only
What are the symptoms of Deep Vein Thrombosis?
DVT forming in the leg can cause pain, tenderness,
redness, perhaps some discolouration of the limb, or a degree
of swelling. The symptoms are more noticeable at the back of the
knee, but the symptoms can be manifest anywhere and they can happen
up to some days after the flight. A common occurrence with passengers
on aircraft is swollen feet or ankles. Swollen feet are caused
because of the low air pressure in the aircraft cabin in conjunction
with poor circulation. While having swollen feet or ankles shouldn’t
cause alarm over the fear of developing DVT, it is a good indication
that blood circulation needs to be taken seriously during a flight.
In some cases there might not be any immediate
symptoms straight after the flight and in extreme cases there
might not be any symptoms in the legs at all. If you find that
you have a shortness of breath, chest pain or other similar symptoms
within a short time after the flight (indeed anytime), you should
consult a medical professional immediately.
If you find you are experiencing any of these
symptoms either singularly or together then you should consult
a medical professional as soon as possible. While the overwhelming
vast majority of airline passengers do not experience problems
of DVT and should not be overly concerned, it always remains a
possibility and should be taken seriously if any symptoms occur.