What a Negative Pressure Room Is
The isolation room that prevents airborne infections from escaping.
How Negative Pressure Keeps Rooms Contained
A negative pressure room uses a ventilation system that pulls air into the room but prevents it from flowing out. This creates lower air pressure inside the space compared to the hallway. Because air naturally moves from high pressure to low pressure, air from the corridor rushes in whenever the door opens. This ensures that any germs inside the room cannot drift out into the rest of the hospital.
When Doctors Use These Rooms
We use these rooms for patients who have diseases spread by airborne transmission. These are tiny germs that stay suspended in the air for long periods, such as tuberculosis, measles, or chickenpox. By keeping these patients in a controlled environment, we protect other vulnerable patients and staff from exposure. You might stay in one of these rooms simply as a precaution while we wait for test results.
Managing the Airflow Safely
The air inside a negative pressure room does not just circulate back into the hospital ventilation system. It passes through a specialized filter called a HEPA filter which removes 99.97% of microscopic particles. After passing through this filter, the air is either exhausted directly outside to the roof or recirculated after being thoroughly cleaned. This multi-step process ensures the rest of the facility remains safe.
Guidelines for Patients and Staff
To maintain this pressure balance, the door must stay closed at all times. Staff wear protective gear like an N95 respirator when entering, which provides a tight seal around the face to filter out fine particles. You may find the room feels slightly different because of the constant airflow, but this is normal. We monitor these rooms constantly to ensure the pressure levels stay correct.
Last reviewed August 15, 2026