Isolation rooms are special hospital rooms that keep patients with certain medical conditions separate from other people while they receive medical care.
Sometimes isolation rooms use negative air pressure to help prevent contagious diseases (such as tuberculosis or flu) from escaping the room and infecting other people. This means that air is constantly being pulled into the room by a machine that then filters the air before it is moved outside. In a negative air pressure room, you may be able to feel air being sucked into the room under a closed door or through a slightly opened window.
In other cases, such as when a patient has a weakened immune system, positive air pressure may be used to keep contagious diseases out of the room. In a positive air pressure room, clean, filtered air is constantly pumped into the room from outside. This prevents "contaminated" air from getting in. With this type of isolation room, you may be able to feel air blowing out of the room under a closed door.
Patients who are being treated in isolation may be allowed to have visitors. But all visitors and hospital workers who enter the room almost always wear masks, gowns, and gloves to prevent the spread of contagious diseases. Everyone entering or leaving the room needs to wash his or her hands thoroughly.