(CNN) — Vacations can quickly spiral into expensive ordeals when illness strikes. Though serious sickness is rare, those who get ill are typically ill-prepared: Less than 20 percent of travelers visiting family or friends in different countries sought medical advice before going.
To combat sickness abroad, prevent it, prepare for it and check symptoms out if you're unsure.
BEFORE YOU GO
Reschedule if you're really sick: If you're violently sick ahead of your trip, it's probably wise to reschedule. The CDC advises air travelers with recurrent vomiting or diarrhea, a fever over 100 degrees, skin rashes and bleeding without injury to avoid flying and seek immediate medical attention. The symptoms could signal more serious illnesses.
Consider travel insurance: Even if you're covered back home, consider buying travel insurance to avoid a steep ER bill. If plans set months ahead change, trip cancellation insurance assures you won't be charged (check travel advisories, too, in case outbreaks or natural disasters strike your destination). If your health insurance doesn't cover care abroad, travel health insurance will. In the rare case your health suddenly declines, medical evacuation insurance pays for your travel back to the US for treatment. Let the US Embassy know: Emergencies are unlikely, but if you register your trip with the US embassy in the country you're visiting, you'll be easily identifiable in case of emergency and can contact family at home.
Stay up-to-date with shots: Some countries in Africa and South America require tourists to get yellow fever vaccines or malaria prevention drugs at least seven to 10 days before they go, depending on the treatment.
WHILE YOU'RE THERE
Know what to avoid: Read up on recommended practices in your host country and those to avoid, like drinking tap water, eating food that isn't cooked or walking barefoot. "Traveler's diarrhea" is the most common illness tourists develop abroad, a form of food poisoning that can last up to a week untreated, so take extra caution during a meal -- even if it looks delicious.
Stay safe: Some countries have curfews, some don't require seat belts in transit or some don't provide life jackets in water sports. Stay aware and avoid what seems unsafe.
Be wary of pets: As impossible as it may sound, don't pet the pets. Animal bites and scratches can transmit rabies, and the vaccine for exposure isn't available in every country.
See a doctor if you need one: If you do fall ill and your symptoms are severe, see a doctor immediately. Local embassies can place you with a physician who speaks the same language, if available.
WHEN YOU'RE BACK
Check for symptoms: Fever and nausea are common after long flights and should dissipate within days, and more likely than not, you're a healthy traveler with a nervous stomach. Still, take symptoms seriously: Consult your doctor when diarrhea lasts more than two weeks or a serious rash persists.
Get checked up, if needed: While only about 8 percent of travelers are sick enough to seek medical treatment once they're home, some symptoms merit a trip to a doctor. Find a clinic that specializes in travel medicine to rule out a (rare) serious illness. They'll likely drill you on the details, so remember what you ate, where you stayed and activities you did there.