Q: My girlfriend and I are planning a five-month backpacking and trekking holiday to India and China. Can you recommend a concise yet comprehensive book of emergency first aid and medicine for travellers?
David Clayson

Dr Jules Eden replies: Recent research now shows that up to 80% of travellers will get some sort of medical problem. Fortunately most illnesses fall into the minor category, like sunburn or diarrhoea. But if left either untreated or poorly managed a trip can turn into a nightmare.

In the countries you are visiting, most prescription medicines are available over the counter. Good news for you, but you need to know which ones to get. I recommend either the concise Lonely Planet guides - they have one specific to Asia - or the bulkier but more thorough Travellers' Health by Dr Richard Dawood (Oxford University Press, £14.99. Don't forget, there's a mine of information on the net if you are stumped for ideas when travelling, and a print out is a lot lighter.

Ask the flying doctor If you have any questions you want to ask Dr Jules Eden, email travel.doctor@theguardian.com, or write to The Flying Doctor, The Guardian, 119 Farringdon Road, London EC1R 3ER.

· Dr Jules Eden created e-med.co.uk as an online support service for anyone who finds themselves a long way from a doctor's surgery. You can get free pre-travel information on any destination in the world. Log on and click on the Travel Clinic icon.