If you're going to be doing any travelling outside your own country, and especially if you'll be staying in a foreign country for any extended length of time, you may be required to have a medical examination done or to provide certain medical records in order to obtain your visa. While each country will have different requirements when it comes to these exams, note a few considerations to keep in mind and to discuss with a travel doctor before leaving, and even after you return from your trip.
A medical exam may include questions about previous surgeries you've had and the reason for such surgeries, as this can tell a doctor quite a bit about your current health risks. For example, knee surgery to repair torn ligaments may not indicate a risk to your health, but open heart surgery may mean that you're at an increased risk of heart attack and other emergency conditions. Be sure you have all pertinent information about any old surgery available, including medications you take due to that surgery, as this information could be needed during your exam and questioning.
Don't assume that your age means that you won't need a medical exam, as even senior citizens and infants may still need to be tested for certain communicable conditions and other health risks. Some countries may even require persons of a particular age to get certain vaccines to protect their health; this might mean a flu shot, a diphtheria vaccination and the like. Whatever the case, don't assume that you will be exempt from an exam and other such treatment just because you're a senior citizen, or that any infants you'll be bringing with you during your travels are exempt.
While many countries may require you to undergo certain health tests and exams before your travels, you might do well to consult with a travel doctor after you return home. It may be rare that you would contract a communicable disease while travelling, but it does happen, and detecting such a condition early on can mean an increased chance of successful treatment. Many people also find that their immune system weakens when they travel, as they go from one climate and one time zone to another, and they may return home with severe colds, a throat infection and so on. A good exam by a travel doctor can note if you might need some medication in order to strengthen your immunity, heal faster and avoid spreading a contagious condition to others.