What Medical Triage Is in a Hospital

Determining Who Needs Emergency Attention First

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The medical definition of triage is the sorting and prioritization of injured or sick people as well as disaster survivors according to their need for emergency care. Resource availability is also taken into account during this process.

Triage may be performed by emergency medical technicians (EMTs), hospital emergency room gatekeepers, soldiers on a battlefield, or anyone with knowledge of the system during an emergency situation.

This article explains what medical triage is, how it works, and when it is used.

Paramedics examining patient on stretcher
Caiaimage / Robert Daly / Getty Images

Why Is It Called Triage?

The word triage comes from the French word trier, which means to sort or select. Its historic roots for medical purposes go back to the days of Napoleon when triaging large groups of wounded soldiers was necessary. Over the centuries, triage systems have evolved into a well-defined priority process, sometimes requiring specific training depending on the setting or organization that uses the system.

How Medical Triage Works

Each organization has its own triage system. They all create priorities for who gets care or is transported for care. The most common triage systems use color-coding.

Examples of the five categories or levels of triage that an organization may use:

  • Red: The individual needs immediate attention for a critical life-threatening injury or illness and may be transported first for medical help.
  • Yellow: The individual has serious injuries that need immediate attention. In some systems, yellow tags are transported first because they have a better chance of recovery than red-tagged patients.
  • Green: This could indicate less serious or minor injuries that are non-life-threatening. Transport may be delayed.
  • Black: This could indicate an individual is deceased or mortally wounded. It may mean that they are beyond help and, therefore, is a lower priority than those who can be helped.
  • White: The individual doesn't have an injury or illness.

Triage systems run the gamut from verbal shouting in an unusual emergency to well-defined colored tagging systems used by soldiers and EMTs when they arrive on the scene of a multi-casualty accident or a battlefield with many wounded soldiers.

When Medical Triage Is Used

In the United States, emergency rooms may be full of people who need immediate attention plus people who are seeking treatment for less serious conditions. The department may be staffed just to meet the expected need. When there are too many patients and not enough personnel or resources, triage is used to determine who gets care first. This ensures the patients who need lifesaving treatment are seen before those who have less serious conditions.

Examples of Triage

Triage may be a short-term need, as when there is a vehicle accident with multiple casualties needing ambulance transportation. Or, it may be a long-term need for a hospital that is often understaffed for the number of patients who arrive at the emergency department.

Triage may also be used for mass casualties in a war zone, a terrorist incident, or a natural disaster that results in many injuries.

Changes to Triage

Triage systems have been changing due to technology. There is increased use of telephones, cell phones, the Internet, and closed teleconferencing systems between trauma centers and rural hospitals that cannot afford the latest equipment or high-level specialties.


Triage is the prioritization of injured or sick individuals based on their need for emergency treatment. Each organization will have their own triage system, which often includes color-coded categories.

Triage may be used to meet an organization's short or long-term needs to help determine who gets care first.

Frequently Asked Questions

  • What do triage nurses do?

    Triage nurses help evaluate patients and decide the priority of care in an emergency room and other medical settings. They update the medical team on the patient's status and provide emergency care when needed.

  • What is telephone triage?

    With telephone triage, a nurse listens to your symptoms and assesses your need for care over the phone. They let you know whether you should see a doctor, go to the emergency room, or try at-home treatment.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Bazyar J, Farrokhi M, Khankeh H. Triage systems in mass casualty incidents and disasters: A review study with a worldwide approach. Open Access Maced J Med Sci. 2019;7(3):482-494. doi:10.3889/oamjms.2019.119

  2. Johns Hopkins Medicine. Electronic triage tool improves patient care in emergency departments. September 25, 2017

Additional Reading

By Trisha Torrey
 Trisha Torrey is a patient empowerment and advocacy consultant. She has written several books about patient advocacy and how to best navigate the healthcare system.