Emergency medicine is unique. At any time of the day or night, practitioners in an ER must be ready to treat any kind of problem, said Dr. Sam Kini, a veteran emergency physician. Patients rush in with everything from chest pains to vaginal discharge. Among the common problems are back pains, abdominal cramps, fevers, bruises and sprains. Kini said the ER is a blend of specialties, and that makes it an invaluable place to teach.