The most carefully planned holiday, business trip or expedition may be ruined by illness, much of which is preventable. It is logical to put as much effort into protecting your health while abroad as you have into planning your itinerary and obtaining the necessary equipment and travel papers.

Unfortunately, it is not in the best commercial interests of travel companies to emphasise the possible health hazards of destinations that are being sold to potential customers: most holiday brochures limit health warnings to the minimum legal requirements, and some travel agents are woefully ignorant of the dangers of travel to more exotic climates. We have recently treated a travel agent for life-threatening malaria caught on the Kenyan coast. He had not taken malaria prophylaxis, despite the long and widespread recognition of the dangers of malaria in this area.

Happily, travellers' health problems are usually more mundane. Fatigue from overwork before a business trip or much-needed holiday, the stress of travel itself, exposure to new climates and over-indulgence in rich food, alcohol and tobacco, all contribute to increased vulnerability to illness. Short-lived episodes of diarrhoea affect up to 50 per cent of travellers, and up to one fifth of tourists on some Mediterranean package holidays will have mild respiratory problems such as head colds, 'flu-like illnesses or, rarely, more severe pneumonias such as Legionnaires' disease. Sunburn or heat exhaustion are common, and accidents associated with unfamiliar sports such as skiing are an obvious hazard. But the most common cause of death among expatriates is road traffic accidents - not exotic infections.

Pre-travel health check-list

Starting three months before you travel, consult your family doctor and specialist agencies, as necessary, to:

1. Obtain information about specific health problems at your destinations.

2. Consider current health, medical and dental fitness and current medications.

3. Obtain adequate health insurance (and form E111 if travelling to an EC country).

4. Check again that health insurance is adequate.

5. Plan and obtain necessary immunisations and malaria prophylaxis.

6. Plan and obtain other medications and first aid items and any documentation.

7. Consider need for first-aid training course.

Sources of information

The depth of preparation required before travel clearly depends on the general health of the individual and on his or her destination(s). In the last few years, accessible information on health for travellers has improved considerably. The sections in this chapter are intended to provide a brief outline of the steps to be considered.

Travellers to areas outside Europe, North America or Australasia are advised to invest in a copy of Travellers' Health: How to Stay Healthy Abroad (3rd edition, OUP) by Dr Richard Dawood - a guide which contains a wealth of information on all aspects of travel medicine. This is updated by regular features in Traveller magazine (published by WEXAS), and is particularly recommended for those planning to work abroad or embarking on prolonged overland trips or expeditions in remote areas.

British travellers should obtain the booklet Health Advice for Travellers Anywhere in the World, prepared by the Department of Health and the Central Office of Information (booklet T5). This contains details of the documentation required for entitlement to free medical care and can be obtained from post offices, GPs' surgeries and vaccination centres, or by telephoning the Health Literature Line (freephone 0800 555 777). The leaflet is also constantly updated, on pages 460-464 of CEEFAX and on the computerised data services PRESTEL and ISTEL to which most travel agents have access.

Some useful web-based sources of information include the Department of Health travel advice (www.doh.gov.uk/hat/index.htm), the Foreign Office (http://193.114.50.10/travel/countryadvice.asp), the American Centers for Disease Control - Travel Health (www.cdc.gov/travel), the World Health Organization (www.who.org), and Shoreland's Travel Health Online (www. tripprep.com/index.html).

When travelling outside Europe, it is wise to obtain information about compulsory immunisation requirements from the appropriate embassy, consulate or high commission of each country that you plan to visit. However, do not expect their personnel to be able to give you general medical advice, and their information is not always as up to date as it should be. British travellers to exotic locations should also consult their District Public Health Department or one of the centres of specific expertise listed in the Directory for the latest information on immunisation requirements and malaria prophylaxis.

Those planning to work abroad should try and contact an employee of the company to ensure that adequate provision for medical and dental care is provided within their contract. If necessary, they should also consider taking out health insurance in addition to company policies.

Medical and dental health

If in any doubt about possible hazards of travel because of a pre-existing medical condition, consult your family doctor. People with heart or chest problems, recurrent blood clots in the legs or lungs, recent strokes, uncontrolled blood pressure, epilepsy, psychiatric disorders or chronic sinus or ear problems may be at risk when flying.

Late pregnancy is a contra-indication to flying, diabetics taking medication will need special advice, and the disabled will have specific requirements that may need to be notified to airline and airport authorities. People with chronic health problems or women who are obviously pregnant should ask their doctor to complete a standard airline form certifying their fitness for flying. This form should be obtained from the airline concerned.

Adequate supplies of all routinely-prescribed medications, including oral contraceptives, should also be obtained before departure. For short trips within Europe, these will be provided as NHS prescriptions. Those planning longer stays abroad should determine the availability of their medication overseas or take adequate supplies (you may need to pay for these on private prescription). It is also strongly recommended that you obtain a certificate from your doctor detailing the drugs prescribed, including the correct pharmacological name, as well as the trade name. This will be necessary to satisfy customs officials and you may need to obtain certified translations into appropriate languages. Some drugs readily obtainable in the UK are viewed with great suspicion elsewhere (codeine, for example, is considered a controlled drug in many countries, and tranquillisers such as diazepam can cause problems). Women working in Saudi Arabia should take adequate supplies of oral contraceptives and will need a certified Arabic translation of the certificate stating that the contraceptives have been prescribed for their personal use.

Those with recurring medical problems should also obtain a letter from their family doctor detailing the condition(s) - the letter can then be shown to doctors abroad if emergency treatment becomes necessary. People with surgically implanted devices are also advised to carry a doctor's certificate to show security officials. Artificial hip replacements frequently set off metal detection security alarms at airports, as do in-dwelling intravenous (e.g. Portacath) central venous lines. People with cardiac pacemakers are unlikely to run into problems due to electrical interference from British or North American airport metal detectors, but should try to avoid going through them and arrange instead for a personal body check by security officials.

Individuals with specific chronic health problems such as epilepsy, diabetes or long- term steroid treatment, should obtain a 'Medic- alert' bracelet or similar, which is more easily located in a medical emergency than a card in your pocket.

Many countries insist on a negative HIV-antibody test before allowing foreigners to work. Some will not allow any known HIV-positive individual to enter the country (http://travel.state.gov/hivtestingreqs.html) despite advice from the World Health Organisation (WHO) that such regulations are ineffective as a means of controlling the spread of HIV infection. HIV-positive travellers should consult their medical specialist and local support groups about specific travel insurance problems and the advisability of travel.

Dental health is often taken for granted by British citizens who get a rude shock when faced with bills for dental work overseas. Those embarking on prolonged travel or work abroad, or planning to visit very cold areas, should have a full preventative dental check up before leaving.

Spare spectacles, contact lenses and contact lens solutions should also be obtained before travelling. If you are planning a vigorous holiday or expedition (e.g. skiing, hill-walking etc.) it might be a good idea to begin an appropriate fitness regime before you leave.

It is worth noting that expatriates taking up a contract abroad will often have to submit to a detailed medical examination as a condition of employment.

On your return

On returning from a long trip, most travellers will experience some euphoria and elation, as well as family reunions and the interested enquiries of friends. After this, as relaxation, and possibly jet lag set in, a period of apathy, exhaustion and weariness can follow. Recognise this and allow a few quiet days if it is feasible. There are usually many pressures at this stage, especially if equipment is to be unpacked and sorted, photographs processed, etc.

Another pressure for most people is the none too welcome thought of returning to the mundane chores involved in earning one's daily bread. If your travels have been challenging, then a couple of recovery days will probably make you work more efficiently thereafter and cope more expeditiously with the thousands of tasks which seem to need urgent attention.

After a time of excitement and adventure, some will go through a period of being restless and bored with the simple routine of home and work. They may not be aware of this temporary change in personality but their families certainly will be. Having pointed out this problem, we cannot suggest any way of overcoming it except perhaps to recommend that everyone concerned try to recognise it and be a little more tolerant than normal. This may not be a sensible time to take major decisions affecting career, family and business.

Some will be relieved to arrive in their hygienic homes after wandering in areas containing some of the world's nastiest diseases. Unfortunately, the risk of ill health is not altogether gone as you may still be incubating an illness acquired abroad - incubation for diseases such as hepatitis or malaria could take a few months or in the extreme case of rabies, a few years.

After your return, any medical symptoms or even just a feeling of debility or chronic ill health must not be ignored - medical help should be sought. Tell your physician where you have travelled (in detail), including brief stopovers. It may be that you are carrying some illness outside the spectrum normally considered. Sadly this has been known to cause mistaken diagnosis so that malaria, for example, has been labelled as influenza with occasionally fatal consequences.

Tropical worms and other parasites, enteric fevers, typhus, histoplasmosis (a fungal disease breathed in on guano, making cavers particularly vulnerable), tuberculosis, tropical virus diseases, amoebic dysentery and hepatitis may all need to be treated. For these illnesses to be successfully treated, many patients will need expert medical attention.

Routine tropical disease check ups are provided by some companies for their employees during or after postings abroad. They are not generally required by other travellers who have not been ill while abroad or after their return. People who feel that they might have acquired an exotic infection or who have received treatment for infection abroad, should ask their doctor about referral to a unit with an interest in tropical diseases. Most health regions have a suitable unit. All travellers who have had freshwater exposure in a bilharzia (schistosomiasis) area (see section on schistosomiasis) should be screened 3 months after the last freshwater contact or sooner if symptoms develop.

All unprotected sexual encounters while travelling carry high risks of infection with various sexually transmitted diseases in addition to HIV and hepatitis B. A post-travel check up is strongly advised, even if you have no symptoms. Your local hospital will advise about the nearest clinic - variously called genito-urinary medicine (GUM) clinics, sexually-transmitted disease (STD) clinics, sexual health clinics, VD clinics or 'special' clinics. Absolute anonymity is guaranteed, and no referral is needed from your general practitioner.

After leaving malarial areas, many will feel less motivated to continue their anti- malarial drugs. It is strongly recommended that these be taken for a minimum of 28 days after leaving the endemic area. Failure to do this has caused many travellers to develop malaria some weeks after they thought they were totally safe. This is more than a nuisance: it has occasionally been fatal.

Fortunately, the majority of travellers return home with nothing other than pleasant memories of an enjoyable interlude in their lives.