CPR, AED & First Aid Glossary

A

Abrasion: A superficial wound caused when the skin is scraped or rubbed against a rough surface.

Acquired Immunodeficiency Syndrome (AIDS): The most advanced stage of infection caused by the Human Immunodeficiency Virus.

Advanced Cardiovascular Life Support (ACLS): Advanced assessment and intervention protocols used by trained healthcare professionals during cardiac arrest and other cardiovascular emergencies.

Airway: The passage through which air travels between the mouth or nose and the lungs.

Allergic Reaction: An immune-system response to a substance that may cause symptoms ranging from mild irritation to a severe reaction.

American Heart Association (AHA): A nonprofit organization that develops science-based guidelines for CPR and Emergency Cardiovascular Care and provides its own training programs.

American Red Cross: A humanitarian organization that provides disaster relief, emergency-preparedness resources and its own First Aid and CPR training programs.

Analyzing: An AED prompt indicating that the device is evaluating the person’s heart rhythm.

Anaphylaxis: A severe, rapidly developing allergic reaction that can become life-threatening.

Arterial Bleeding: Bleeding from a damaged artery that may be rapid or pulsing and can result in significant blood loss.

Automated External Defibrillator (AED): A portable device that analyzes heart rhythm and may instruct the user to deliver an electrical shock when a shockable rhythm is detected.

AVPU: A responsiveness scale representing Alert, responsive to Voice, responsive to Pain or Unresponsive.

Avulsion: A wound in which skin or other tissue is partially or completely torn away.

Axillary Region: The area under the arm commonly called the armpit.

B

Bag-Valve-Mask (BVM): A handheld ventilation device used by trained responders to deliver breaths through a face mask.

Barrier Device: A face shield, pocket mask or similar device designed to reduce direct contact during rescue breathing.

Basic Life Support (BLS): Foundational emergency-response care that includes recognizing cardiac arrest, performing high-quality CPR, using an AED and responding to airway emergencies.

Bleeding: The loss of blood from a damaged blood vessel. Bleeding may be internal or external.

Bloodborne Pathogen (BBP): A disease-causing microorganism present in human blood that can infect people who are exposed to it.

Body Substance Isolation (BSI): An infection-control approach that treats blood and certain body fluids as potentially infectious.

Brachial Artery: A major artery in the upper arm commonly used by trained responders to check an infant’s pulse.

Burn: Tissue damage caused by heat, chemicals, electricity, radiation or friction.

C

Capillary Bleeding: Bleeding from small blood vessels near the skin’s surface that commonly appears as slow or steady oozing.

Cardiac Arrest: The sudden loss of effective heart function, causing circulation to stop.

Cardiopulmonary Resuscitation (CPR): An emergency procedure that uses chest compressions, with rescue breaths when appropriate, to help circulate blood during cardiac arrest.

Carotid Artery: A major artery in the neck where trained responders may check for a pulse in an adult or child.

Chain of Survival: A sequence of coordinated actions associated with improved cardiac-arrest outcomes, including early recognition, CPR, defibrillation, advanced care, post-arrest care and recovery.

Chest Compression: Rhythmic pressure applied to the chest during CPR to help circulate blood.

Chest Compression Fraction (CCF): The percentage of total resuscitation time during which chest compressions are being performed.

Chest Recoil: The chest’s return to its normal position after each compression, allowing the heart to refill with blood.

Child: For CPR purposes, an individual approximately one year old through the onset of puberty.

Choking: A partial or complete airway obstruction caused by food, an object or another substance.

Clear: A verbal warning used to ensure that no one is touching the person during AED rhythm analysis or shock delivery.

Commotio Cordis: Sudden cardiac arrest caused by a blunt impact to the chest during a vulnerable moment in the heart’s electrical cycle.

Compressions-Airway-Breathing (C-A-B): The sequence emphasizing chest compressions before opening the airway and providing breaths during CPR.

Contaminated Sharps: Needles or other sharp objects contaminated with blood or other potentially infectious material that can puncture the skin.

D

Defibrillation: Delivery of an electrical shock intended to stop certain dangerous heart rhythms so an organized rhythm may resume.

Dehydration: A condition in which the body loses more fluid than it takes in.

Dislocation: An injury in which the bones forming a joint are forced out of their normal alignment.

E

E-C Clamp: A hand-positioning technique used by trained responders to hold a ventilation mask while helping maintain an open airway.

Emergency Medical Services (EMS): The system of trained responders and services that provides out-of-hospital emergency care and transportation.

Epinephrine: A medication used in the emergency treatment of severe allergic reactions.

Epinephrine Auto-Injector: A device designed to deliver a premeasured dose of epinephrine.

Exposure Incident: Contact of the eyes, mouth, mucous membranes, non-intact skin or bloodstream with blood or other potentially infectious material during work duties.

External Bleeding: Blood loss from a wound that is visible outside the body.

F

First Aid: Initial assistance provided for an illness or injury until the condition resolves or additional help becomes available.

First Aid Kit: A collection of supplies and protective equipment used when responding to common injuries and emergencies.

Foreign-Body Airway Obstruction: A partial or complete blockage of the airway by food or another object.

Fracture: A crack or break in a bone.

G

Gastric Inflation: Air entering the stomach during ventilation, often because breaths are delivered too forcefully or rapidly.

H

Hands-Only CPR: CPR using continuous chest compressions without rescue breaths, commonly recommended for a bystander who witnesses a teen or adult suddenly collapse.

Heart Attack: Damage to heart muscle caused when blood flow to part of the heart becomes blocked. A heart attack is different from cardiac arrest.

Hepatitis B Virus (HBV): A virus that infects the liver and can spread through blood and certain other body fluids.

Hepatitis C Virus (HCV): A virus that infects the liver and is primarily spread through exposure to infected blood.

Human Immunodeficiency Virus (HIV): A virus that attacks the immune system and can lead to AIDS if untreated.

I

Infant: For CPR purposes, a child younger than one year.

Infection Control: Practices designed to reduce exposure to and transmission of infectious microorganisms.

Internal Bleeding: Blood loss occurring within the body that may not be externally visible.

L

Laceration: A cut or tear in the skin or underlying tissue.

M

Medical Emergency: A sudden illness, injury or change in condition that may require immediate assistance.

Mucous Membrane: Moist tissue lining areas such as the eyes, nose and mouth that may provide a route for exposure to infectious material.

N

Naloxone: A medication that can rapidly reverse the effects of an opioid overdose.

No Shock Advised: An AED prompt indicating that the device has not detected a heart rhythm for which a shock is recommended.

O

Occupational Safety and Health Administration (OSHA): The federal agency responsible for setting and enforcing workplace safety and health standards in the United States.

Opioid: A class of drugs that includes prescription pain medications and illegal drugs such as heroin.

Other Potentially Infectious Materials (OPIM): Certain human body fluids, tissues and other materials identified by OSHA as potential sources of bloodborne-pathogen exposure.

P

Personal Protective Equipment (PPE): Equipment such as gloves, protective clothing, masks and eye protection used to reduce exposure to hazards.

Pocket Mask: A barrier device with a one-way valve used when providing rescue breaths.

Poisoning: Illness or injury caused by swallowing, inhaling, injecting or absorbing a harmful substance.

Pulse: The pressure wave created in an artery each time the heart contracts.

Puncture Wound: A wound caused when a pointed object penetrates the skin.

R

Recovery Position: A side-lying position used to help maintain an open airway in an unresponsive person who is breathing normally.

Rescue Breath: Air delivered into another person’s lungs during assisted ventilation.

Respiratory Arrest: The complete cessation of effective breathing.

Responsiveness: A person’s ability to react to voice, touch or another stimulus.

RICE: A traditional acronym representing Rest, Ice, Compression and Elevation in the care of certain soft-tissue injuries. Current guidance may vary based on the injury and organization.

S

Seizure: A sudden burst of abnormal electrical activity in the brain that can affect movement, awareness, behavior or sensation.

Severe Bleeding: Rapid, continuous or substantial blood loss that may become life-threatening.

Shock: A life-threatening condition in which the body’s tissues do not receive adequate blood flow and oxygen.

Shock Advised: An AED prompt indicating that a shockable heart rhythm has been detected.

Source Individual: A person whose blood or other potentially infectious material may be the source of an occupational exposure.

Sprain: An injury involving stretching or tearing of ligaments around a joint.

Standard Precautions: Infection-prevention practices used based on the possibility of exposure to blood, body fluids, non-intact skin or mucous membranes.

Strain: An injury involving stretching or tearing of a muscle or tendon.

Stroke: A neurological emergency caused when blood flow to part of the brain is blocked or when a blood vessel in the brain ruptures.

Sudden Cardiac Arrest (SCA): An abrupt loss of effective heart function that causes circulation to stop.

T

Tourniquet: A device designed to restrict blood flow through an extremity when responding to life-threatening bleeding.

Trachea: The airway commonly called the windpipe that carries air toward the lungs.

U

Universal Precautions: An infection-control concept that treats human blood and certain body fluids as potentially infectious. Standard Precautions expand upon this approach.

V

Ventilation: Movement of air into and out of the lungs, either naturally or with assistance.

Ventricular Fibrillation (VF): A life-threatening heart rhythm in which the lower chambers quiver instead of pumping blood effectively.

Venous Bleeding: Bleeding from a damaged vein that commonly produces a steady flow of darker-colored blood.

Vital Organs: Organs necessary for life, including the brain, heart and lungs.

W

Wound: Damage to the skin or underlying tissue caused by injury.

X

Xiphoid Process: The small lower portion of the sternum.

Related Online Certification Courses

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• CPR/AED Certification
• First Aid Certification
• Basic Life Support Certification
• Bloodborne Pathogens Certification
• First Aid for Severe Bleeding Certification
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Important Information

This glossary provides general educational definitions. It does not provide complete response procedures, replace formal instruction or substitute for professional evaluation or emergency services.

In an emergency, contact the appropriate local emergency-response service.