Medical tourism is one of the hottest topics in health care as patients around the world are increasingly traveling abroad for treatment.

Josef Woodman, author of Patients Beyond Borders, a guide to medical tourism, told CNN that two to three million people travel outside their home country for treatment each year, while consultancy firm Deloitte calculates that 750,000 Americans traveled abroad for treatment last year.

The top regional destination for medical tourists is Asia, with Singapore, Thailand and India leading the way. Those countries are home to private health care chains that target international patients and are building modern, high-tech hospitals with a reputation for quality care.

Bumrungrad International Limited (BIL), based in Thailand, owns and operates over 70 health care facilities in seven countries. According to BIL, its Bangkok flagship hospital treats over 400,000 foreign patients a year, with over 90,000 coming from the Middle East.