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Travel health information for people travelling abroad from the UK

Air Travel - Health Issues

Airline Restrictions on Flying

Airlines have the right to refuse to carry passengers with conditions that may worsen, or have serious consequences, during the flight. Airlines may require medical clearance from the medical department/adviser if there is an indication that a passenger could be suffering from any disease or physical or mental condition that:

  • May be considered a potential hazard to the safety of the aircraft.
  • Adversely affects welfare and comfort of the other passengers and/or crew.

Travel by air is normally contraindicated in the following cases:

  • Infants less than 48 hours old (longer after premature births).
  • Women after the 36th week of pregnancy (32nd week for multiple pregnancy).
  • Those suffering from:
    • angina or chest pain at rest
    • any active communicable disease (see further notes)
    • decompression sickness after diving
    • increased intracranial pressure
    • infection of the sinuses or of the ear and nose and eustachian tubes
    • recent myocardial infarction
    • 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.

Communicable 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.

The airline has the right to 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 (e.g. spots following chicken pox) is advised to 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.

The following table is a guide to communicability periods of some infections. If in doubt about an individual traveller, they should be assessed by a doctor.

DiseasePeriod of Communicability
Chicken pox 1-2 days before onset or rash and continuing until all lesions have crusted (usually about 5 days after) - longer in the immunocompromised.
Influenza Up to 3-5 days from clinical onset. Up to 7 days in young children.
Measles From 1 day before prodromal period (usually 4 days before rash) to 4 days after rash.
Mumps Up to 7 days before to 9 days after onset of parotitis - maximum infectiousness 2 days before to 4 days after.
Pertussis (whooping cough) Highly contagious in early catarrhal stage and at beginning of paroxysmal cough stage (first 2 weeks). Thereafter decreases until negligible at 3 weeks.
Rubella 1 week before and at least 4 days after onset of rash; highly communicable
Tuberculosis Until at least 2 weeks following effective treatment.


The World Health Organization advises that, with tuberculosis 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. WHO further advises that physicians should inform all infectious TB patients that they must not travel by air until they have completed at least two weeks of adequate treatment. Patients with multidrug resistant TB should be advised not to travel until proven by adequate 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 and may miss out on professional and personal opportunities. There is no single personality type, prone to fear of flying and there may be a link with problems at work or home.

Fear may develop from a bad experience - a rough flight, or after a news report of a high jacking or crash. Panic attacks are common (sudden, intense anxiety, sweating and trembling). The sensation is often so frightening that the sufferer may refuse to fly in the future.

Advice for the Traveller who is Afraid of Flying

  • Explain that fear of flying is common and emphasize that flying is safer than road or rail travel in most developed countries.
  • Try distraction by talking with other passengers, watching in-flight films, eating or reading.
  • Tell the cabin crew. Reassurance about strange sounds can help.
  • A visit to the doctor prior to travel can provide reassurance about general fitness for air travel.
  • Mild sedation before departure is sometimes used but this should be a decision made on medical grounds. It must be stressed that these drugs do not mix well with alcohol.

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.

Courses and Counselling on Fear of Flying

  • Aviatours provide courses at Heathrow and Manchester airports (Tel: 01252 793 250).
  • 'Freedom to Fly' courses are run independently by Elaine Iljon Foreman, clinical psychologist (Tel M: 07966540731  L: 01243 920161, email:, website:

Security in Aircraft

None of the following are allowed in British Airways aircraft cabins (similar regulations are likely to be introduced by other airlines):

  • Toy or replica guns (plastic or metal).
  • Household cutlery.
  • Knives with blades of any length (including steel nail files).
  • Paper knives.
  • Razor blades.
  • Tradesmen's tools.
  • Darts.
  • Scissors of any size.
  • Hypodermic syringes.*
  • Knitting needles.
  • Sporting bats (including rackets, cricket bats and golf clubs).
  • Billiard, snooker, or pool cues.
  • Catapults.
  • Corkscrews with blades attached.

*Customers who require the use of hypodermic needles for medical reasons (for example, diabetics and customers with allergies), will be asked for proof of medical need. Please be advised that customers carrying any of the above items (with the exception of hypodermic needles) will be asked to place it in their hold baggage. Customers carrying hand baggage only will be asked to surrender the item for disposal by British Airways.

Further advice may be available from the airlines concerned or from British Airways Medical Service who also provide a useful booklet 'Your Patient and Air Travel' giving advice on fitness to travel and specific contraindications.

In-Flight Problems

See also NHS Choices on preventing deep vein thrombosis when travelling.


The circulating air in aircraft cabins is dry since there is very little moisture in the air taken from outside the cabin to replenish supplies when the planes are at high altitude. Skin moisturizers can help alleviate dry skin and lips and if contact lenses irritate they should be removed and spectacles used instead if necessary.

There is no evidence that the dry air results in significant internal dehydration in those otherwise fit and well. Alcohol (especially spirits) and caffeine containing drinks can however cause dehydration especially when inadequate clear fluids are taken - passengers should try and drink sufficient to keep the urine its normal pale colour.

Poor Circulation and Venous Thrombosis

Last updated 24/07/07

Sitting still for long periods in the inevitably cramped positions in aircraft frequently leads to swollen ankles and sometimes muscle cramps. Venous thrombosis in the legs and occasionally pulmonary emboli can occur but this is not unique to air travel and can occur whenever people are immobile for prolonged periods, including long bus, train and car journeys. Preventive measures should include general advice to all passengers, including ensuring good hydration, restricting alcohol and coffee intake, regular stretching and mobility exercises.

Those with the following may be at greater risk and this should be assessed in advance of travel by the patient's doctor:

  • A history of deep vein thrombosis within the last 5 years or if the likely reason for this DVT is still present.
  • Disseminated malignancy and chronic debilitating illness especially those causing serious immobility problems.
  • Recent surgery or deep injuries (e.g. hip fractures).
  • Those over 60 years of age.
  • Pregnancy or less than 2 months after delivery.
  • Cardio-respiratory disease.
  • Oestrogen medication (contraceptive and/or hormone replacement).
  • Raloxifene or tamoxifen.
  • Varicose veins.
  • Thrombophilia especially when due to the presence of factor V Leiden mutation.
  • Obesity.

Advice for those thought to be a special risk includes the general preventive measures described above and the use of graded elastic compression stockings (while reducing ankle swelling, their role in preventing thrombosis is less certain). For those at serious risk a single subcutaneous injection of low molecular weight heparin, given shortly before departure should be considered so long as anticoagulation is not contraindicated. Aspirin has not been shown to be effective and is no longer recommended.

Air Rage

This term has recently been introduced to describe psychological or physical violence occurring within 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 often a developing cycle of events, which may include delays, exhaustion due to lack of sleep, excessive use of alcohol sometimes to compensate fear of flying, minor irritations due to behaviour of fellow passengers which elsewhere would largely go unnoticed and sometimes anoxia causing irritability in those with pre-existing hypoxic illnesses. It has recently been recognised that air rage may be contributed to by nicotine withdrawal in heavy smokers on long distance flights. Smoking against the rules in the toilets, for example, can precipitate a disturbance.


Nicotine gum may be useful prophylaxis. Passengers should avoid excessive alcohol consumption and discouraging heavy drinking by their travelling companions. Airlines have the right to refuse to carry those who have previously caused disruption on a flight - warnings may be issued (the equivalent of yellow/red card system as used at football matches).

Jet Lag

Changes to Circadian Rhythms

These regulate our sleep patterns, 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 (e.g. 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.
  • Stretch and exercise as much as possible to aid circulation and prevent swollen ankles.
  • Drink plenty of water or soft drinks and remember alcohol in spirits and wine and also caffeine increase dehydration (caffeine is present in coffee, tea, chocolate, Coca and Pepsi Cola).
  • Jet lag is made worse by a hangover!
  • Avoid heavy commitments on the first day. Be prepared for tiredness in the evenings and early waking which can last up to 5 or more days.
  • After arrival hypnotics (sleeping tablets) have been shown to help and correspondingly alertness during the following day. They do not speed up adjustment the new time zone and therefore may need to be used for several nights.
  • Some travellers find taking regular melatonin helpful. It may help the body to adjust its circadian rhythms but its effect is scientifically unproven. It is not readily available in the UK but can be purchased in some countries such as the US and Hong Kong from health food shops or pharmacies.

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 sited above 2400 metres, for example, in the Andes and Himalayas - healthy people can then develop symptoms after arrival (headache, nausea, breathing difficulty, mental confusion).

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 hypoxic 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. An estimate of the degree of hypoxia occurring on exercise may be able to predict whether they will experience problems.

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