Contacting your physician prior to international travel is very important. Many areas of the world have diseases which are not common here in the United States. You may need special vaccinations or medications to prevent these infections. If you are taking any prescription medications, you will need an extra supply and written prescriptions to help you pass through international customs. Your family doctor can also give you advice about over-the-counter medications you may want to take with you, how to prevent many illnesses, and what to do about an illness should it occur out of the country.