An emergency room (often called an ER) is a special part of a hospital designed to treat people who need immediate medical help for serious injuries or sudden illnesses. If someone breaks their arm badly, has trouble breathing, experiences severe chest pain, or gets badly burned, the emergency room is where they go for urgent care that can't wait for a regular doctor's appointment.

Emergency rooms stay open 24 hours a day, every day of the year, because medical emergencies don't follow a schedule. Doctors and nurses in the ER are trained to make quick decisions and handle many different problems, from heart attacks to deep cuts that need stitches. When you arrive at an emergency room, staff quickly assess how serious your condition is through a process called triage. The most critical patients get treated first, which means someone with a twisted ankle might wait while doctors help someone having a heart attack.

The emergency room differs from an urgent care center, which handles problems that need attention soon but aren't life-threatening, like a mild fever or a possible sprained wrist. If someone is unsure whether something counts as an emergency, medical professionals at an ER can help decide what kind of care is needed.