"I think medicine is a profession that requires you to give your soul and develop a therapeutic bond with someone," he says. "If someone has a hateful perspective towards you, it naturally gets in the way of your ability to deliver that kind of care, because you're not necessarily able to develop that therapeutic bond."

He stresses that most patients never express biased views or behaviors. "But over long careers, these types of episodes do happen. And they sit with doctors for a long time."

Those experiences also stay with the nurses who encounter them -- including Valda Boyd Ford, a registered nurse.

Ford says that on her first day of work at a Jacksonville, NC, hospital, a patient told her to "get my black [email protected]# out of his room."

"It felt ugly, but I didn't have a choice. I had to go back in there. That particular day, we were swamped," she says. "Even though I wanted to cry … I had a job I had to do, and I did it."

Nurses may be even more vulnerable to abuse than doctors because of the extra time they spend with patients. "The doctors may be in the room for 3 to 5 minutes. The nurses can be in there for an hour or more," says Ford, who is founder and CEO of the Center for Human Diversity. The center aims to improve communication between people of different racial, ethnic, social, and cultural backgrounds.

The survey found that nurses (23%) and nurse practitioners (18%) were more likely to hear comments about their weight than other health care professionals.

Incidents of bias in health care settings have also attracted attention thanks to social media.

Last summer, a video circulated on the Internet of a woman demanding a "white doctor" for her son at a Canadian walk-in clinic. The woman asked an employee, "Can I see a doctor please that's white, that doesn't have brown teeth, that speaks English?"

Security escorted the woman from the building, and a doctor treated the child.

Tamika Cross, MD, an African-American doctor who volunteered to help a sick patient on a flight, says she was told by a flight attendant they were looking for “actual physicians or nurses.”

“Whether this was race, age, gender discrimination, it's not right,” Cross wrote on a Facebook post detailing the incident.