Urdu, Mandarin, Haitian Creole... By the thousands each week, they pass through the doors of Elmhurst Hospital in a part of New York City that is home to perhaps a greater diversity of foreign-born immigrants than any comparable community in the world.

Spanish, Korean, Albanian...

A broken bone is the same in any language, but not so diabetes or hypertension--abstractions for which many people do not have words. The very concept of organic illness varies from culture to culture. If you were brought up to believe that your symptoms arise from sorcery or from something you did in a previous life, you might not grasp the necessity for a course of chemotherapy whose most immediate and obvious effect will be to make you feel a hundred times worse. And if well-educated people in New York, Paris or Singapore sometimes find it hard to keep track of the complicated regimen of medications for, say, heart failure and diabetes together, it surely is no easier for a Pashto speaker relying on her grandson to explain how to measure her blood sugar.

The immigrant phenomenon isn't new, but never before have developed countries' medical teams--with their increasingly specialized and technologically advanced techniques--faced the challenges presented by newcomers from such a diversity of cultures and faiths. "Hmong [a Laotian ethnic group with a rural culture] will smile and nod when they're with the doctor, but they have no intention of taking the pills," says Sa Vang, a fourth-year medical student at the University of California, Davis, whose parents came to the United States in 1979. "My grandmother would only take her blood-pressure medication when she had a headache." Vang has seen this happen many times in her community: patients who take their pills in response to a specific symptom, which may or may not be related to the condition the drugs are supposed to treat. The patient doesn't want to offend the doctor, so he says he's been taking his medicine; the condition hasn't improved, so the doctor increases the dosage, to the point where the patient starts to experience side effects. The result: "Patients think the doctors don't know what they're doing."

The best-documented case of such misunderstandings involved Lia Lee, the daughter of a Hmong family in Merced County, Calif., in the 1980s. When she was 3 months old, she fainted on hearing the sound of a door slamming. Doctors assumed the seizures she suffered after that were from epilepsy, but her parents provided their own diagnosis, the temporary disappearance of her soul out of her body, a condition whose name translates as "the spirit catches you and you fall down" (which was the title of an excellent book by Anne Fadiman on Lia's case). Whether modern medicine could have controlled her epilepsy is unknown; what Fadiman found was that Lia's competent and dedicated doctors prescribed more than a dozen different drugs in various dosages and combinations that changed 23 times in four years. Her well-meaning parents, illiterate even in Hmong, followed the doctors' orders only sporadically, but sent away to Thailand for sacred amulets, and changed Lia's name to fool the evil spirits--a plan that failed, according to her mother, because the doctors insisted on calling her Lia. Four years after her first symptoms, she suffered a massive seizure and septic shock that left her in a persistent vegetative state, where she remains today. She is 22.

How many smaller dramas are being played out in hospital corridors is anybody's guess. On the periphery of France's biggest cities, where hospitals serve increasingly multi-ethnic and multifaith neighborhoods, hallway prayer sessions are a common sight, patients sometimes decline emergency-room treatment by medical staff of the opposite sex, and women have given birth in burqas. Isabelle Levy, author of "La religion a l'hopital" ("Religion at the Hospital"), talks of a "cultural screen" between patient and health workers. In February, French Health Minister Philippe Douste-Blazy issued a circular reaffirming nondiscrimination and religious freedom in medical care, as long as it doesn't impede treatment, and he guaranteed patients the right to decide on their own care--when it doesn't go against their own best interests. As health practitioners gradually integrate the minister's order, they continue to improvise, when they must. "The result ends up being a sort of dialogue," says Mathieu Valla, a sixth-year medical student and intern who has worked in an ethnically mixed northern suburb of Paris. "It isn't official, but when a child's life is in danger, we override the parents' beliefs if we must. With adults, it tends to be case by case." France's newly arrived East European, sub-Saharan African and Asian communities each present their own unique challenges. "With many Asian immigrants," says Valla, "if I put a hand on their stomach or head to suggest a stomachache or a headache, they don't understand. It's very frustrating."

Even when patient and doctor share a common language, racial differences can get in the way of communications. "When I was in medical school, there was lots of talk about disparities in health care, but it focused on access," says Dr. Maren Grainger-Monsen, director of the Bioethics in Film Program at Stanford. "Then we learned that minorities with equal insurance and access still had drastically worse outcomes in cardiac surgery and lung cancer." Grainger-Monsen believes the "shocking" disparity can be attributed, in large part, to cultural differences and failures of communication. Her new film, "Hold Your Breath," recounts the case of Mohammad Kochi, an Afghan immigrant who was treated in California for stomach cancer. After his surgery, doctors recommended chemotherapy, but Kochi refused to undergo an unpleasant treatment that might not work. His real objection emerged much later: his doctor had prescribed a continuous intravenous infusion of chemotherapy, but Kochi was a devout Muslim who could not let foreign fluids enter his body after he had cleansed himself for prayer--a prohibition that he believed extended to an IV drip.

A trained medical interpreter might have gotten to the root of Kochi's problem sooner, but he had relied on one of his daughters, who had her own ideas about which information her father should receive. When his doctor told him that he still had cancer after the surgery, she refused to translate that information, fearing it would upset him. Dr. Joseph Betancourt, director of multicultural education at Massachusetts General Hospital, recalls how as a 7-year-old he was asked to mediate between a doctor and his Spanish-speaking grandmother. Simple ignorance of medical terms was compounded by embarrassment; his grandmother was suffering from uterine cancer. "We still see kids acting as the cultural brokers for their families," says Betancourt, "but it's no way to run a hospital."

The medical profession has its own traditions, of course, and humility did not always rank high among them. But physicians increasingly realize that, simple human dignity aside, respecting patients' cultural beliefs can avoid tragedies like Lia Lee's. As Sa Vang shows by her own example, many of the problems will lessen as immigrants assimilate. She knows that disease is not caused by evil spirits' snatching the soul out of the body. Her husband doesn't really believe that either, but neither does he let their two young sons attend funerals, where the evil spirits are especially active. And Sa Vang, the medical student, doesn't object.