Why do my feet and ankles swell on flights and in hot or humid climates, such as Malaysia?
One leg is more affected than other and swelling is better, but still evident 24 hours after the flight.
This is a commonly asked question about a problem that frequently causes concern to travellers and is highly topical in the light of recent media attention to the risk of developing deep vein thrombosis(DVT) on long haul flights.
Under normal circumstances, the blood circulates around the body, reaching the legs, the periphery of our circulation via the arteries.
In order to get back to the heart having delivered its oxygen to the tissues, the blood is aided by the natural pumping action of the muscles in our legs and the one-way non-return valves that are built into our veins, allowing blood to flow only in the direction of the heart.
When we are in hot or humid climates, our peripheral circulation opens up in order to assist heat loss from the body and control temperature, preventing overheating.
We also tend to perspire more heavily for the same reasons and can become salt-depleted as a result.
The loss of salt from the circulation can reduce the ability of the veins to draw blood back in from the tissues, leaving the fluid in the limbs causing them to swell.
The process is not helped by the veins being dilated because of the heat.
When we remain seated for long periods of time without exercising the legs or if one becomes relatively immobile for whatever reason, the lack of muscular action may also cause swelling of the legs to occur.
Therefore a combination of a hot climate and relative inactivity makes the ideal scenario for lower limb swelling.
Exercising the legs and elevating them will help, as will ensuring an adequate salt intake.
Often one leg may be slightly more swollen than the other, relating to a past history of varicose vein surgery or injury and/or infection of the veins.
However, one has to bear in mind the possible diagnosis of thrombosis and if one leg persists in being swollen, even in the absence of other symptoms, medical assessment is advised to put your mind at rest.
The NetDoctor Medical Team
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