High summer travel costs coupled with unrest around the world from natural disasters, civil revolts and terrorism worries have led more consumers to look closely at travel insurance.

You better look very closely. Travel policies come in handy for unexpected illnesses and typical air-travel weather fiascoes, but they are usually filled with exclusions that often negate coverage for many cancellations. Most policies exclude coverage if a trip is canceled because of a pregnancy, pre-existing medical issues or an injury from playing organized sports, scuba diving or skydiving. If a hurricane damages your hotel but doesn’t render it “uninhabitable,” the policy may not reimburse you if you cancel. Terrorism protections may only cover you if an attack happened in your destination city within 30 days of your trip. And there’s typically no coverage in standard policies for cancellations because of war, nuclear disasters, epidemics or civil unrest.

One way around the fine-print: Buy “cancel for any reason” coverage. It’s more expensive, but far more effective. There are still a few rules in many policies, such as requirements to cancel 48 hours before departure.

Sales of cancel-for-any-reason policies at InsureMyTrip.com, a comparison shopping site, are up 15% so far this year compared with the same period in 2010—significantly faster growth than for standard policies. One reason is the world-wide travel caution issued by the U.S. government after the killing of Osama bin Laden.

“If it’s anxiety that is causing you to cancel, it would have to be a cancel-for-any-reason policy,” said Jim Grace, chief executive officer of InsureMyTrip.com. “Those policies give you the ability to make the decision yourself.”

Standard policies have many exclusions to protect insurance companies from crippling claims, said U.S. Travel Insurance Association spokeswoman Linda Kundell. “Like all insurance, travel insurance is based on risk,” she said. “If absolutely everything under the sun was covered, claims would go so high the companies would be out of business and the insurance would be worthless.” She adds that more situations are covered than excluded: “The majority of claims that are filed are paid.”

At least 20% of all travelers have some kind of insurance protecting them on the road, according to the association, though many have insurance through credit-card benefits or their regular auto, home and medical insurance. In 2008, travelers spent about $1.6 billion in travel insurance premiums. The highest growth areas for the past several years have been separate travel medical-insurance policies, since some health-insurance programs, including Medicare, limit overseas coverage.

You can buy travel insurance directly through your airline, cruise line or packaged-tour company, or you can buy an independent policy sold through travel agents or online vendors like InsureMyTrip.com and Squaremouth.com. Standard policies cost about 4% to 10% of the total cost of the trip; cancel-for-any-reason coverage typically costs about 6% to 12% of the trip.

American, Delta Air Lines, United Airlines and US Airways all offer insurance from Access America, a unit of Allianz’s Mondial Assistance Group. It’s priced from 4.5% to 7.5% of the total ticket cost, depending on the level of coverage offered. Airlines and Access America say the level of insurance offered is often based on the type of trip, the type of ticket and how many people are traveling together.

Carriers say sales are up—AMR Corp.’s American Airlines says a single-digit increase in sales began last year amid all kinds of travel disruption, such as the volcanic ash cloud and fierce winter weather.

Access America and Delta recently began testing a “cancel anytime” policy costing 6.5% to 7.5% of the ticket price that reimburses 100% of what you paid in the event of job loss, injury or illness; 80% is reimbursed for most other unforeseen reasons.

Most airline policies include at least $10,000 in medical and dental coverage and $50,000 for medical evacuations. That can be a huge help if you break a tooth or a leg, or need to spend a night in a hospital, but it likely isn’t enough to cover any sort of extended stay or international private medical jet transportation. But for less than what you pay through airlines, you can buy an independent policy with $50,000 medical and dental coverage and $250,000 or more in evacuation coverage.

Most airline-sold policies have a travel-delay benefit that reimburses $200 in food and lodging expenses if your flight is delayed six hours or more; some of the more expensive airline policies have baggage-delay coverage as well. Independent policies priced about the same on Squaremouth.com and InsureMyTrip.com come with $1,000 or more per person travel delay insurance (usually with a $150 to $200 daily limit). They also will pay for essentials during baggage delays, with extra coverage for baggage loss.

Norwegian Cruise Line says its insurance sales are up because trip costs are higher. “When people spend more money, the risk of something happening to that vacation is more significant to them,” said Crane Gladding, the cruise line’s senior vice president of revenue management and passenger services.

Trip-cancellation insurance covers losses on airline tickets, non-refundable hotel bookings or pre-paid cruise and tour bookings. With airlines, that can often mean paying only the airline’s change fee if you rebook. But often in severe weather situations, airlines not only waive change fees and penalties, but also allow full refunds if they cancel your flight. In those cases, insurance never comes into play.

Natural disasters like earthquakes typically aren’t covered for cancellation, but most policies will offer to help pay to get you home if your trip is interrupted by a natural disaster. That can come in handy if airlines charge the full fare for highly coveted seats during mass evacuations. Chris Harvey, chief executive of Square
mouth.com, says some insurers have even started offering “non-medical evacuation” policies that would help travelers flee situations like the uprisings in Egypt.

Hurricanes are particularly tricky, and terms can vary widely. Once a storm gets a name, or in some policies even is a tropical depression with a number, then any insurance you buy after that won’t cover that particular storm.

• If you are worried about bad weather disruptions…

…consider first whether you are likely to rebook. Airlines typically will waive change fees or give refunds if flight schedules have widespread cancellations from storms, and cruise lines and hotels will rebook as well.

• If you are worried about getting sick before your vacation, or an illness or death of a family member…

…check policies carefully for pre-existing conditions, which can negate coverage. Many policies require injuries and illnesses to be disabling or even require hospitalization.

• If you are worried about missing your cruise because of flight delays or even an auto accident on the way to the port…

……arriving a day early is the best insurance. Travel insurance likely would reimburse your out-of-pocket costs, however.

.• If you are worried about losing your job before your big, expensive vacation and may need to cancel…

…get a policy with job-loss coverage. Some require you to be in the job for a year, some for three consecutive years. Most only cover layoffs and won’t pay if you are fired for cause.

• If you are worried about medical costs overseas…

…ask your health-insurance provider for what coverage you have overseas, and make sure it’s good in countries you will be visiting. If not, consider a medical-only policy that will help pay for medical and dental costs and emergency medical evacuation.

• If you are worried about terrorism, unrest, natural disasters, subject to military duty deployment or concerned about injury from your sports league…

…upgrade to a ‘cancel for any reason’ policy. It will cost more, but cover more.