Jules Eden, travel medicine specialist and founder of e-med, answers travellers' questions - as published in the following national publications

• The Guardian
• Independent On Sunday and/or
• Geographical Magazine

Q. Any tips for a diabetic about to go to Thailand for some trekking?

A. The travelling diabetic has to be aware of a few factors that can ruin their holiday. It starts with arrival at the airport in Thailand. If you are carrying syringes and needles with you it is a good idea to have a letter explaining your problem. I once met a diabetic that was kept overnight in the airport cells of a certain country as he had been reported by the in-flight crew as a potential drug abuser as they had seen him self injecting on the plane. If the letter was written in Sinhalese, that would be even better. I believe the British Diabetic Association has a supply of these.

If you are insulin dependent then you may need to keep your insulin supply cool whilst in the jungle. There are cool packs you can buy to do this.

Finally, if you get any illness that may derange your blood sugar, such as diarrhoea or other infections then monitor your blood glucose regularly and treat the illness quickly with appropriate antibiotics. Be prepared, take some with you. Ciproxin is probably one of the best broad spectrum ones going.

Q. Exactly a year ago my wife had an operation for malignant melanoma in which thirteen lymph nodes were removed from her armpit. She developed a clot on the lung, but this was quickly treated with warfarin. The cancer hadn't spread and since then she's been fine, and we've made several trips together involving short haul flights to Europe.

In April, however, we're planning to fly to Atlanta (9 hours). She's confident that she'll be fine, but is there any medical reason why she shouldn't make such a long flight? Your advice welcomed.

A. I do not see that there should be any real problems. The removal of lymph nodes in the armpit can make her prone to swelling in the arm, and on rare occasions this could bring on a thrombosis ni the veins of the arms, rather like a DVT in the leg.

But this is “hen’s teeth” as we say medically. The reason DVT’s develop in the leg in-flight is that the legs are folded, cramped and move little. Hence the blood gets static and clots develop. As long as she does not let her arm hang there with no movement for the full 9 hours she will be fine.

The thing to watch, though, is other melanomas developing. There is an increased risk if she has had one before, and it can get hot there in the Southern States.

Make sure she has plenty of sun block, and if you see any spot or freckle getting darker, or irregular around the edge, then get it to a dermatologist as soon as possible.

Q. Please could you advise me where best to take my 13 year old son on holiday over Easter? He has been unwell since last September and as yet we have no definite diagnosis. It is possibly Crohn's disease. He is quite depressed and I would like to take him somewhere where he could relax and gather some strength. I do not have a great deal of money but helping him feel better is my main consideration.

A. I assume that if the inflammatory bowel disease, Crohn’s, is suspected then he must be having symptoms of loose and frequent motions, tiredness, and maybe some joint pains too.

So you must go somewhere where the food is not too spicy or strange which could worsen the problem.

On top of this, long flights will be tiring and expensive, and there’s got to be something to cheer him up cheaply at the other end.

I have a couple of thoughts, and welcome any more from readers.

Eurodisney by train would fit the bill.

But for something a bit more unique, why not try Western Ireland. Easy to get to, good simple food that he would be used to and, importantly, dolphins.

Just being near one, close enough to touch will cheer up the most hardened sad soul. Nature’s Prozac, especially for a teenager.

Q. I'm going to the Galapagos Islands next month with my wife who has happily found out that she is 6 weeks pregnant. My question is will it be safe for her to travel there and maybe also take in a trip to the Amazon as we have some extra time in Equador, or should we be rethinking the whole destination?

A. I don't think you have to necessarily cancel the trip at this stage, but you may well have to adapt it to fit in with your wife's pregnancy.

The main thing is with immunization and malaria prophylaxis.

Pregnancy is divided up into 3 thirds called trimesters, and the most crucial time for the development of your child is in the first trimester. It is during these 12 to 14 weeks that all the sensitive embryonic developments of limbs and other organs occurs, and anything that can have an effect on the fetus here will cause far more serious problems later. 2 of the vaccines your wife should have for an extensive trip to Equador can theoretically cause problems if given in the first trimester. These are Yellow Fever and the newer Hepatitis A shot. Now, she will mainly be at risk of getting Yellow Fever if you both go down to the Amazon, as it is a disease spread by mosquitoes that are lowland and forest based. So I suggest that if she hasn't previously been vaccinated against this (within the last 10 years) then she should avoid it and that you both stay away from the Amazon Basin, but head to higher ground if you have some spare time. I can recommend Banos south of Quito.

She is unlikely to encounter Yellow Fever in the Galapagos, so that should be fine. As for the Hepatitis A shot, I would recommend she have the old style immunoglobulin as that is much safer in this trimester, but sadly it is getting harder for us doctors to get hold of as the manufacturers are annoyingly ceasing its production in favour of the more expensive alternatives.

She will need to take malaria prevention whilst away, but for that part of Equador the combination of chloroquine and paludrine should be fine, and they are both safe to take in pregnancy.

Other issues in her case are that whilst you are enjoying the close up animal encounters and snorkelling with sharks, she may well be throwing up in a bucket every morning. Morning sickness is a problem up to 14 weeks when levels of the hormone HCG drop, and as she will be also on a boat for a lot of the time then it might be an idea to take antiemetic tablets with her. Probably the best ones in her circumstances are called metaclopramide and her doctor should give you a scrip for these.

As she doubtless knows she must avoid certain foods at this time, especially undercooked eggs and soft cheeses. I suggest that you both learn the Spanish for these items, so when you are presented with a plate of food of ambiguous origin, you can ask the chef quickly and politely if it contains these products. It beats entertaining other diners with your chicken impressions as you try to fathom the food's contents in sign language.

She cannot dive of course but snorkelling would be fine at 10 weeks of pregnancy. I think the real message here is that if you are a keen traveller then get both Hep A and Yellow Fever in early as they both last 10 years and similar problems with a later pregnancy wouldn't occur.

Q. I have recently undergone a knee replacement on both knees. It is now 3 weeks since the operation but I have been invited skiing by some friends in March. My question is this, will I be fit enough by then and is there anything I can do to increase my chances of being fit to ski by then?

A. It seems you have really picked a sport here that is going to test your knees.

A knee replacement is quite a big operation to have, and the fact that you have had one on both knees obviously doubles your potential for harm if you come a cropper on the slopes.

The usual guidelines for an operation to return you to normal afterwards is 8 to 12 weeks, but the doctors then only expect you to do a little light exercise.

Skiing puts a tremendous strain on your knees as they have to be flexed or bent when you go down the slope to act as shock absorbers for the rest of the body. If you skied with straight knees not only would you fall over far more easily but also the chances of causing hip or lower back problems is increased.

So the question is, is can you effectively keep your knees bent for the time it takes to get down a run and also to do it several times a day. By going in March you are close to the time when you should be fine to do it but there are a few other mitigating factors. If you are overweight then you will be putting more pressure on the knees so you must make sure you are as close to your normal weight as you can possibly be before going. Another factor is what we call quadriceps wasting. These are the muscles in the front part of your thighs that are again used a lot in keeping your knees flexed. If the condition that necessitated your knee replacements has let these muscles in your leg waste away then you will find it very hard to keep up with your fellow skiers.

My advice is that March may be a little too early to get back to a full on skiing adventure like you may have enjoyed before you got your knee problems. But with some good physiotherapy, working on building up your quadriceps, and losing as much weight as is deemed healthy you will probably be able to at least go on the green and blue runs, but again I would advise that you to stay away from mogul fields or particulary bumpy uneven runs as they will again cause extra grief to your post op knees.

So long flat smooth runs with as little turning as possible, why not try the USA.

Q. I'm flying to Antigua next week with both my children. However the oldest Zoe, who is 3 has come into contact with another child who has since developed chicken pox. What are the chances she will get it too, and will she be allowed to fly if she does have it?

A. This is a question that I am being frequently asked at the moment as we are right in the middle of chickenpox season.
I understand your concern as it is impossible to tell if Zoe will contract it from her friend and when it will come. You obviously don't want to cancel your holiday only to find that she remains in perfect health, and neither do you want to turn up at the check in desk just as the spots erupt to be told you cannot board.
There is a lot of conflicting information around but for your circumstances this is what I advise.
The incubation period for chickenpox can be anything from 7 to 20 days. So you can have a long wait to see if Zoe is going to develop the illness. However , during this incubation she is not contagious until she is about to come up with the rash. You can tell this is about to happen as she will develop symptoms like that of a cold. She will be snuffly, may have a fever and be generally unwell and clingy. If this happens the chances are that she is about to erupt in blister like viral filled vesicles, and, as she will be infectious you should cancel the flight.

If she remains well over the next week then she is unlikely to be incubating the illness and you should go ahead with the holiday as planned. Of course there is a chance that with a maximum of 20 day incubation that she could go down with the illness whilst you are in Antigua.

Once she has the spots then she will be infectious to others until the very last spot has finally crusted over and fallen off and should not fly.

Chickenpox is caused by a variant of the Herpes virus, and is spread by respiratory droplets, so if she coughs or sneezes then she can infect anyone in the vicinity.

This creates the difficulty with flying as air is recircrculated around the plane so others may breathe it. Therefore there is a danger that any passenger may contract the disease. This can be a disaster if anyone on board has AIDS or is immunosupressed after a transplant as chickenpox can be fatal in these people.

So if Zoe stays well this week feel free to board the plane and enjoy your holiday, but if she begins to fall ill then cancel as soon as you can. This will be reimbursed by your insurance policy.

A. This may well be a close call.

Don't worry about the statin, it just lowers the cholesterol and is fine at altitude.

However the beta blocker could be a problem. It's a drug that reduces blood pressure by slowing down the heart.

At altitude, as the oxygen is decreased, your heart would compensate by increasing its beats per minute rate before other physiological changes happen. With a beta blocker it cannot. The issue here is that you must really make sure you do the absolute minimum whilst you wait to get used to the altitude. It can take up to 3-4 days to acclimatise, but on the beta blockers give it at least 5. If you go for any trekking take it really easy up the slopes.

An alternative may be to switch to a different blood pressure tablet. Try losartan, one of the newer ones that won't slow your heart rate.

A. This is the time of year that tearful parents bid farewell to their now adult children. I've done it to my mother and my child will do it to me someday. Perhaps, the modern equivalent of a young Masai killing his first lion. The perils are different but it is possible to go much better prepared than carrying a rusty assegai!

As he is asthmatic he must take a good supply of inhalers. Your GP will be happy to prescribe enough for the trip and it depends what his daily use is, as to how many that is. Inhalers have a long shelf life and don't need to be kept chilled. It is advisable to always carry one in a waist belt rather than have the whole supply in a rucksack. Theft of his possessions is always a risk, so make sure it doesn't cause a medical problem as well by not keeping all the eggs in one basket.

I also suggest that he takes some broad spectrum antibiotics in case of a chest infection. Amoxicillin should be good enough unless he has a penicillin allergy, though my favourite antibiotic for travellers, ciproxin, would be better as it can cover a wide range of infections, from bowel to ear.

If he is diving, take a "fit to dive" medical certificate as some Asian countries will not let him dive with asthma without one.

There has been some interesting research lately about asthma and volcanoes. They have been implicated in the precipitation of bad attacks, rather like thunderstorms have been. It could well be the ash from the lava, but I suggest doubling his inhaler dose if he is near one.

Take a good travel health guide. Lonely Planet do an excellent range. Small and portable they are invaluable and cost little.

Finally he must have good travel insurance cover. Make sure it includes any activity he may do and if it covers diving, check the depth it covers too. The cheaper ones only go to a shallow depth, he will need cover to 30 metres depth at least.

Do not worry though, the health services are excellent in Asia, and with e-mail he can get quick advice from home if he needs.

And don't forget the shots and antimalarials.

Q. We are planning to go to New Delhi, and also to travel around India (although not sure where yet). Although we consider ourselves fairly experienced travellers, and India has always been on our "list", we are slightly wary of the implications of a full bout of Delhi Belly on my husband, who is an insulin-dependent diabetic. How do we maintain a stable blood sugar during a prolonged bout of diarrhoea?

A. Your husband must obviously take his blood sugar testing kit with him. If he gets a bad bout of diarrohea then his blood sugar can dramatically fall to low enough levels to bring on a hypoglycaemic attack. This is where the diabetic gets initially angry and irritable, lapsing into tiredness and potentially a coma. You must be aware of these symptoms as well in case he fails to recognise the problem.

Take some rehydration sachets such as Dioralyte or Electrolade with you. If he gets the problem, monitor his blood glucose 1 to 2 hourly and use the sachets to keep his sugar stable. I would also take a course of the antibiotic ciproxin with you. If he gets any loose bowels take a 750mg dose as a one off. This will often stop the diarrohea in a day thus preventing serious problems later if it runs its course unchecked. Get a scrip from our GP for this.

Finally make sure he has a doctors letter explaining his condition, as there are tales of the local police taking a dim view of travellers carrying syringes and needles.

Q. My wife is 36 weeks pregnant with our second child.

We are going to the South of France in a week on the Eurostar train.

My question is do you think she will be fit to travel all that way and back, and will we need a note to show them when we get on at Waterloo to say it's OK to travel on the train.

A. I would suggest you check with the operators of the Eurostar service as to what they exactly need.

The only real comparison, of course, is with airline travel.

Here International flights usually rule that no one can fly after 32 weeks of pregnancy, but they can end the rules and often let people fly up to 36 weeks if they have a doctors note to say all will be well.

To be frank I don't know how your GP can guess that all will be well in a couple of weeks as we know that premature labour catches everyone by surprise.

If you need a note your doctor will check that the babies head is not fully engaged and there are no contractions. If all is clear then you should be fine.

For the return leg don't travel if there are any signs of labour.

Other useful tips are to make sure you have the E111 form with you. This allows you free health care in France if you needed to see an obstetrician.

On the trip itself make sure she gets up to take a walk up and down the carriage every hour.

The pregnant uterus can press on the venous drainage from the legs and so increase the risk of a DVT. So a little stroll will sort that out.

Finally, and I'm sure you were going to do this, but it's best if you carry all the luggage!