This page tells you about certain health issues you should be aware of when you fly, including Deep Vein Thrombosis, or flying after SCUBA diving.

Important: If you have an existing medical condition, this may be affected by flying, so please read this information carefully to find out what you need to do. Our Special Assistance team can help make sure you're cleared to fly.

For most of us, flying is a safe way to travel. However, the pressurised cabin can potentially affect passengers with existing medical conditions, people who have recently been SCUBA diving, and people at risk of Deep Vein Thrombosis (DVT). See below for further details. If you’ve had a general anaesthetic or dental treatment within 48 hours prior to your flight, you won't be able to fly.

Please be aware that our cabin crew may spray insecticide in the passenger cabins at the start or end of some flights. This is harmless to humans. You can find out more information from the US Department of Transport.

To reduce the risk of decompression sickness, you will need to leave ample time between your last SCUBA dive and your flight.

If you have only had a single dive, you may fly 24 hours after, if the dive did not include decompression stops.

If your dive involved a decompression stop or you’ve been on more than one dive, you should leave 48 hours before you fly.

Deep Vein Thrombosis (DVT) is a serious condition where blood clots develop, most often within the deep veins of the legs. Anyone sitting for more than four hours is at risk of developing DVT, but you may be at greater risk if you:

  • Are aged 40 or over 
  • Have previously been diagnosed with blood clots 
  • Have a family history of blood clots 
  • Have inherited a blood clotting risk 
  • Have cancer and/or you are undergoing cancer treatment 
  • Are being treated for heart failure and/or circulation problems
  • Have had recent surgery, especially on the hips, knees, or abdomen 
  • Have an illness which has led to a period of immobility 
  • Are pregnant or recently had a baby 
  • Take the contraceptive pill or other medicines containing oestrogen 
  • Are very tall, very short or obese

If you think you are at risk, please talk to your doctor before your flight to find out how to reduce your chances of developing DVT.

If you’d like further advice after seeing your medical practitioner, you may find the following contacts useful:

  • Our ever-helpful Special Assistance team can be reached on (+44) 0344 412 4455 
  • The UK Civil Aviation Authority website has advice for both medical practitioners and passengers – follow the links to the Aviation Health Unit

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