For the great majority of people with cancer air travel shouldn't be a problem. But do remember that even for those of us who are fully fit modern day flights can still be a stressful business so someone who is very unwell would probably find it difficult to cope.

In general terms, air travel is extremely safe. Even among those travellers who warn airlines in advance that they have a health problem it is uncommon that a person requires special attention during their flight. The great majority of these episodes relate to heart conditions and difficulties due to cancer seem to be very rare.

Some people with cancer may be advised not to travel by air under particular circumstances, as oxygen levels and air pressures change at high altitudes.

You may be advised not to fly if:

• You are breathless.
• You are anaemic (have a low number of red blood cells).
• You are at risk of developing an increased pressure or swelling in the brain (cerebral oedema) due to a brain tumour.
• You have recently had surgery or a medical procedure – as this can introduce gas into the body that may expand to cause pain and stretch your wound. Air travel should be avoided for 10 days after any surgery.
• You have recently had surgery to your chest. Air travel should be avoided for 3 – 4 weeks after chest surgery. After chest surgery you should have a chest x-ray to make sure that the lungs are fully expanded before flying.
• You have recently had surgery to your brain.
• You have problems with your ears or sinuses, where pressure changes may make symptoms worse.

Anaemia is a common problem for people with cancer and if a long flight is being planned then it would be just as well to have a routine blood test to check the haemoglobin level. This is normally about 12 to 15. It is only when the level falls to 8 or below that there might be any problems with flying. Usually when the blood has fallen to this level other symptoms are quite obvious (like breathlessness, tiredness and weakness). Often a simple blood transfusion can correct the anaemia for a while and would allow someone to fly safely.

For people who have lung and breathing problems as a result of their cancer their specialists will usually be able to arrange simple tests of lung function which will give a guide as to whether or not it is safe for them to fly. These tests can be done as an outpatient, on the NHS, and are quite painless.

If lung function tests show a moderate degree of loss of respiratory function then it might be possible to overcome this problem by arranging to have a special supply of oxygen to use, with a mask, during the flight - either continuously or to breathe as and when needed. Most airlines can arrange the oxygen supply if they are notified in advance, although some of the newer cut-price companies do not offer this service. It is useful to check the costs before you book the flight - although many airlines will provide the oxygen supply free of charge others have fees of as much as £100 per flight (ie £200 for a return journey). If someone uses a pressurised inhaler to help with their breathing it is perfectly safe to use these during a flight.

Another group of people who have had cancer who might experience problems whilst flying are those who have had surgery for head and neck cancer and have a tracheostomy. This is because the atmosphere in planes is very dry and during a long flight this can dry out the normal secretions which moisten a tracheostomy which might lead to discomfort or distress. The problem can be avoided by using a portable humidifier but this would only be necessary occasionally. The best thing is, if someone has a tracheostomy, for them to have a chat with their specialist and get advice if they are thinking of going on a long flight.

Some people with cancer may have a higher risk of developing blood clots (thromboses) than other people. If you are worried about the risk, it is best to discuss this with the cancer specialist who can advise whether treatment to help to prevent blood clots is necessary. All air travellers should drink plenty of non-alcoholic fluids during flights and it is helpful to walk around or do leg exercises regularly.

In addition all airlines have well qualified medical departments and if you contact them before flying they will always be able to give help and guidance.