di Pop quiz: if you're having chest pains, should you go to an urgent care center or the emergency room? The answer should be obvious. Yet according to a new poll, patients suffering from real medical emergencies like this one are not heading to the ER. Seven in 10 emergency physicians treat patients who end up in the ER only after first going to urgent care centers -- and learning that their medical problems were too serious to be treated there. As urgent care centers explode in popularity, it's critical that Americans understand the difference between urgent care and emergency care. Choosing an urgent care center over an ER during a medical emergency could cost a patient his life. There are currently some 9,000 urgent care centers nationwide. These facilities fill an important gap in the health care system for patients who need time-sensitive care but can't wait to see a primary care physician or don't have one. Urgent care centers are often open on weekends and evenings, in addition to normal business hours. Most don't require appointments. They're generally able to provide routine treatment for simple health problems, such as ear infections, strep throat, or sprains, on a first-come, first-served basis. And they often have on-site X-ray machines to diagnose simple fractures. Emergency departments, on the other hand, are always open and ready for whatever comes through the door. The sickest patients in an ER generally go to the head of the line. Some emergency conditions are more obvious than others. Most people would not hesitate to go to the ER for a gunshot wound, for instance. But something like slurred speech also requires a trip to the emergency room. It's a symptom of stroke, which can kill 2 million brain cells a minute. Delaying treatment by even minutes can be the difference between a full recovery and death. Patients may not think that their condition screams "emergency." But even fairly benign symptoms can be warning signs of a life-threatening condition. Consider abdominal pain. Perhaps it's just an intestinal virus. But it could be a ruptured bowel, which requires emergency, life-saving surgery. It's an emergency physician's job -- not a patient's -- to know the difference. And these emergencies can only be managed at one place -- the emergency department. Part of the problem is that patients are misinformed about the role of urgent care centers. Consumers are often swayed by their relatively low prices and marketing. Indeed, more than half of ER physicians say that urgent care centers in their communities advertise themselves as an alternative to emergency rooms. Take Nason Medical Center, which offers urgent care services in South Carolina. It was recently ordered by the state's Department of Health and Environmental Control to stop using the word "emergency" to advertise itself because it confuses patients. Such intervention by government officials is valid, considering that misinformation can put patients at risk. BroMenn Medical Center in Chicago has reported that since last August, five patients have come to the ER with heart attacks -- after first seeking care elsewhere for their chest pains. Patients can't be expected to diagnose themselves. Those with the symptoms of a medical emergency should go to the emergency department. Delaying critical care by going to the wrong medical facility might make the difference between life and death. Michael Gerardi, M.D., is president of the American College of Emergency Physicians. Warning signs of a medical emergency: http://www.emergencycareforyou.org/EmergencyManual/IsItAnEmergency/Default.aspx?id=122 Symptoms of childhood emergencies: http://www.emergencycareforyou.org/EmergencyManual/IsItAnEmergency/Default.aspx?id=124