I suffered a painful burst ear drum during my flight home from Menorca a couple of years ago. It was suggested that I had perhaps picked up an infection swimming. My doctor tells me that the ruptured membrane has repaired itself, but that it is scarred. I have arranged to fly in a couple of months' time and would like to know how to minimise the risk of suffering a recurrence. My doctor has suggested taking anti-histamine tablets a few hours before the flight, but I remain apprehensive.
Allen Parks

Dr Jules Eden replies: When you ascend, air expands and needs to escape from the middle ear via the Eustachian tube. When you descend, air contracts and more has to be blown into the middle ear. If you have any problem with this tube, thus affecting its ability to pass air in and out, then you risk middle ear damage as well as a blown ear drum. I advise taking a Sudafed tablet two hours before you need to equalise. It contains pseudoephedrine, an adrenalin-like substance that constricts the lining of the Eustachian tube, thus widening its diameter.

· I have a problem with low blood flow through my right femoral artery due to injury from the insertion of a coronary angiogram catheter a year ago. I keep myself in good physical condition (I am 68) to help this low blood flow condition. Would I have any problems with clots resulting from flying?
Chuck Vostry

Dr Jules Eden replies: Fortunately for you, an injury to the artery may even help in the prevention of deep venous thrombosis (DVT) rather than cause it. It's all about blood flow to and return from the leg. More in and less out will enhance this problem, whereas less in and the same out will not.

DVT is a consequence of too much blood lying static in your legs. A clot forms, bits of which break off and enter the lungs, resulting in a life threatening pulmonary embolus.

So if you were accidentally injured during an angiogram, the fact that less blood is getting down to your legs means that there should be no extra precautions needed for a flight.

· 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.