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Air Travel - Health Issues

Airline Restrictions on Flying

Airlines can refuse to carry passengers with conditions that may worsen, or have serious consequences, during a  flight. Airlines may request medical clearance if there is an indication that a passenger could be suffering from an unstable medical condition:

Travel by air is not normally advisable in the following cases:

  • infants less than 48 hours old (longer after premature births)
  • women after the 36th week of pregnancy or 32nd week for multiple pregnancy
  • those suffering from:
    • angina or chest pain at rest
    • any active infectious disease
    • decompression sickness after diving
    • increased intracranial pressure (due to bleeding, injury or infection)
    • infection of the sinuses
    • recent heart attack
    • recent stroke
    • recent surgery or injury where trapped air or gas may be present (e.g. abdominal trauma, gastrointestinal surgery, craniofacial and ocular injuries, brain surgery or eye operations)
    • severe chronic respiratory disease
    • breathlessness at rest
    • unresolved pneumothorax
    • sickle cell anaemia
    • psychotic illness, except where fully controlled.

The above list is not exhaustive so any potential traveller with an underlying medical condition who is unsure, should seek advice from their GP in the first instance. Airlines' regulations may vary so if in doubt advice should also be sought from the medical department of the airline concerned. Most airlines have a medical advisory service such as British Airways Medical Service

Infectious Diseases

Research has shown that there is very little risk of any infectious disease being transmitted on board an aircraft. The quality of the aircraft cabin air is carefully controlled. However, transmission of infection may occur between passengers who are seated in the same area of an aircraft, usually as a result of a cough or sneeze or by touch. This is no different from being close to someone in any other form of transport such as a bus or train.

An airline can refuse travel to any passenger who is unwell and they suspect may be contagious. Anyone who has recovered from an infectious disease, but still shows signs, for example spots following chicken pox, should carry a letter from their GP confirming that they are no longer infectious.

In order to minimise the risk of passing infections in an aircraft, passengers who are actively unwell, especially if they have a fever, should delay travel until they have recovered.

Where an individual has travelled and is subsequently found to have a serious infectious illness with potential risks to other passengers, for example measles, contact tracing of passengers will be carried out by public health authorities.

The following table is a guide to communicability periods of some infections. You should seek medical advice if there is any doubt regarding whether it is appropriate to fly or not.

Disease Period of Transmission
Chicken pox 1-2 days before onset or rash and continuing until all lesions have crusted (usually about 5 days after) though it can be longer in some cases.
Influenza Up to 3-5 days from onset of symptoms. Up to 7 days in young children.
Measles From 1 day before initial symptoms such as fever or headache, usually 4 days before rash, to 4 days after rash.
Mumps Up to 7 days before to 9 days after onset of parotitis (inflammation of the paropatid gland) seen as swelling to the side of the face, maximum infectiousness 2 days before to 4 days after.
Pertussis (whooping cough) Highly contagious in early catarrhal stage and at beginning of cough stage, the first 2 weeks. Thereafter decreases until negligible at 3 weeks.
Rubella 1 week before and at least 4 days after onset of rash; highly transmissible.
Tuberculosis Until at least 2 weeks following effective treatment.

Tuberculosis (TB)

The World Health Organisation (WHO) advises that, with TB increasing worldwide, there is a small but real risk of infection being transmitted during air flights. Transmission has only been recorded in flights lasting over eight hours. The risk is clearly greater when many of those on board are from countries with a high incidence of the disease. Infectious TB patients should be informed by their doctor that they must not travel by air until they have completed at least two weeks of adequate treatment. Patients with multidrug resistant TB should not travel until proven by laboratory confirmation to be non infectious. To date no case of active TB has been identified as a result of exposure on a commercial aircraft.

Fear of Flying

In Britain an estimated nine million people suffer anxiety about flying. There is no single personality type, prone to fear of flying it may develop following a bad experience such as a rough flight, or after a news report of a high jack or a crash. Panic attacks are common, the sensation is often so frightening that the sufferer may refuse to fly in the future. Fear of flying is often underpinned by a fear of losing control but fear of turbulence, terrorism, feeling trapped, claustrophobia or fear of heights can all be contributing or causative factors.

Advice for the Traveller who is Afraid of Flying

  • Fear of flying is common despite flying being safer than road or rail travel in most developed countries.
  • Try distraction by talking with other passengers, watching a film, listening to music or reading.
  • Tell the cabin crew. Reassurance about routine aircraft sounds and in flight activities can help.
  • A visit to the doctor prior to travel can provide reassurance about general fitness for air travel.

Cognitive Behaviour Therapy

Recent research has indicated that cognitive behaviour therapy can be helpful for more severe cases. The person identifies what they actually fear and then learns different ways of overcoming it. Your GP may be able to refer you to a suitable therapist.

Courses on Fear of Flying

A number of airlines run courses aimed at alleviating travellers fears, such as:

Security in Aircraft

World events in recent years have led to a marked increase in airport and aircraft security. Restrictions on equipment and fluids being taken into the aircraft cabin can have implications for travellers who need to carry medication for use during the flight. In addition, travellers are advised  to pack medications and essential medical equipment into hand  luggage, with additional supplies in their hold luggage. Passengers who use hypodermic needles for medical reasons, for example those with diabetes or allergies, may be asked for a doctor’s letter as proof of the medical need.

In-Flight Problems


The circulating air in aircraft cabins is dry as there is very little moisture in the air taken from outside the cabin to replenish supplies.. Skin moisturisers can help alleviate dry skin and lips and if contact lenses irritate they should be removed and spectacles used instead.

There is no evidence that the dry air results in significant dehydration in those otherwise fit and well. Alcohol (especially spirits) and caffeine containing drinks can cause dehydration especially when inadequate clear fluids are taken, passengers should try and drink sufficient non-alcoholic beverages.

Deep Vein Thrombosis (DVT)

Prolonged periods of immobility can lead to slow blood flow in the veins which increases the risk of developing deep vein thrombosis (DVT). Blood clots most commonly form in the lower extremities; parts of the clot may break off and travel to the lung where they can cause a pulmonary embolism (PE) which is potentially life threatening.

See the Deep Vein Thrombosis advice page for detailed information.

Air Rage

This term is used to describe psychological or physical violence occurring within an aircraft. It is of particular concern because of the cramped conditions inside an aircraft and the inevitable involvement of not only the cabin crew but also other passengers. There have been instances where aircraft have had to land prematurely to offload disruptive passengers and legal action taken against those involved.

What is Air Rage?

There is no one cause of air rage but likely combinations of stress factors and a developing cycle of events. Contributing factors include:

  • Anxiety precipitated by airport security checks and a feeling of loss of control.
  • Tiredness due to lack of sleep, extended travel, delays etc.
  • Excessive use of alcohol, sometimes used to compensate for fear of flying; in addition the effect of alcohol is enhanced at altitude. It is estimated that alcohol intoxication accounts for 1 in 3 air rage incidents.
  • Lack of space, space restrictions and infringement of personal space can cause discomfort and irritability.
  • Nicotine withdrawal in heavy smokers (nicotine gum or patches are useful).
  • Minor irritations due to behaviour of fellow passengers which elsewhere would largely go unnoticed can become disproportionate.

Jet Lag

Changes to Circadian Rhythms

These regulate our sleep patterns and need time to adjust to changes in local time, usually about one day per time zone crossed. Westward travel may be better tolerated than eastward travel but problems occur when travelling in both directions. The effects of jet lag include: sleep disturbance, loss of appetite, nausea and sometimes vomiting, bowel changes (for example constipation), general malaise, tiredness and poor concentration.

  • A relaxed flight is important.
  • Avoid travelling when you are already tired and take rest before departure.
  • Remember the actual home to destination travelling time will usually be at least twice the actual time spent in the air since it will include waiting in airports and often unexpected delays.
  • Breaking very long journeys halfway with a stopover can be helpful.
  • On the flight get maximum sleep or take frequent naps.
  • Stretch and exercise as much as possible to aid circulation and prevent swollen ankles.
  • Drink plenty of water or soft drinks and remember alcohol and caffeine increase dehydration (coffee, tea, chocolate and many carbonated soft drinks contain caffeine).
  • Avoid heavy commitments on the first day after travelling. Be prepared for tiredness in the evenings and early waking which can last up to 5 or more days.
  • Establish a new routine by eating and sleeping at the correct times at the destination.

Altitude Sickness After Landing at High Altitudes

High altitude is generally considered to be from 2400 metres (8000 feet). Aircraft cabins are maintained at a pressure approximately equivalent to between 1800-2400 metres and so altitude sickness symptoms are not usual during flights.

A few airports are situated above 2400 metres, for example, in the Andes and Himalayas - leading to symptoms of acute mountain sickness after arrival such as: headache, nausea, breathing difficulty, mental confusion. Symptoms usually develop up to 36 hours after arrival at altitude.

Those with pre-existing respiratory or cardiac problems may be more likely to experience symptoms during or after flights. Being aware that they may be due to altitude can be helpful. Dehydration may make symptoms worse as may strenuous exertion.

Those with serious pre-existing respiratory disease may need to seek specialist advice before planning air flights and sometimes request, in advance, supplementary oxygen supplies in flight or after arrival. See also Altitude and Travel.


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