BEFORE YOU GO
A little planning before departure, particularly for pre-existing illnesses, will save you a lot of trouble later. See your dentist before a long trip; carry a spare pair of contact lenses and glasses (and take your optional prescription with you); and carry a first aid kit with you.
It is tempting to leave it all to the last minute- don't! Many vaccines don't ensure immunity until two weeks after they are given, so visit a doctor 4 to 8 weeks before departure. As your doctor for an International Certificate of Vaccination (otherwise known as the yellow booklet), which will list all the vaccinations you've received. This is mandatory for countries that require proof of yellow fever vaccination upon entry, but it's a good idea to carry it wherever you travel.
Travellers can register with the International Association for Medical Advice to Travelers (IAMAT, www.iamat.org ). It's website can help travellers to find a doctor with recognised training.
Bring medications in their original, clearly labelled, containers. A signed and dated letter from your physician describing your medical conditions and medications, including generic names, is also a good idea. If carrying syringes or needles be sure to have a physician's letter documenting their medical necessity.