While millions of tourists swarm to Brazil each year to experience the lush rainforests and bustling cities, an increasing number are visiting with a different agenda—to receive cosmetic surgery.

Although traveling abroad to receive medical treatment dates back to ancient Greece, the recent influx of “medical tourism” has garnered public attention. In his latest book, “Patients with Passports: Medical Tourism, Law, and Ethics,” Harvard Law School Professor I. Glenn Cohen explores various forms of medical tourism and their associated legal and ethical issues.

“Medical tourism is not the most intuitive topic; it’s a very sophisticated discussion,” said Professor Nathan G. Cortez, Assistant Professor of Health Sciences at Southern Methodist University, who has collaborated with Cohen on his work.

“You’re talking about medicine, law, and international dimensions, which adds up to very difficult but provocative phenomena,” he said.

Cohen’s own investigations were influenced by both increasing media reports and his own personal experience.

“I grew up in Canada, where many Canadians would go across the border to receive MRIs,” he said.

Cohen says that medical tourism has noticeably increased in the past 12 years due to the ease and diminishing costs of travel, increasing healthcare costs, and globalization.

Although patients in Canada may seek treatment abroad to avoid long waiting times, the demographics of medical tourism are evolving and expanding.

“It has usually happened from countries with weaker medical systems, but now there’s a focus in wealthier countries,” said Professor Jeremy C. Snyder from Simon Fraser University, who is currently developing guidelines for Canadian patients considering foreign medical care.

While wealthy foreign patients have traditionally come to the US for perceived higher quality treatment or procedures and technology unavailable at home, patients from the U.S. are increasingly traveling to Mexico, India, and China for cheaper or experimental treatment. Popular cross-border services include cardiac surgery, hip and knee replacement, cosmetic surgery, and stem cell therapy. A standard knee replacement, which costs an average of $45,000 in the U.S., can be performed for $6,500-$13,000 in India.

Cohen’s book, which will be published in late 2013, discusses the two categories of medical tourists: those seeking medical procedures that are legal in their home country, such as coronary artery bypass surgery and hip replacement surgery, and those seeking controversial or illegal procedures including organ sale and abortion.

He also describes the myriad of problems associated with each category, including quality of care, adequate documentation, doctor-patient relationship, and proper patient information.

“I was shocked at the number of parents taking their children abroad for stem cell therapy to treat conditions such as neurodegenerative and other diseases without strong evidence,” said Cohen.

Given the unlikelihood that the pressures fueling medical tourism will abate, Cohen believes it will be important to promote general awareness and knowledge and hopes his book will aid in that effort.

Although medical tourism will likely persist in a regulatory void for the forseeable future, Cohen recommends that countries provide better innovation pathways, more effective methods of organ procurement, and improved cooperation between state and foreign governments in the near term.