The first priority during a medical emergency is to save lives. A person who is unconscious and unresponsive may be close to death, and rescuers must assess the situation and begin treatment as needed to restore and maintain the person's airway, breathing, and circulation (the ABCs). A problem in any of these areas may be fatal if not corrected quickly.
The airway, which is the passage through which air travels to the lungs, can become blocked (for example, by choking on or inhaling a piece of food). Many disorders, such as emphysema and asthma, can make breathing difficult. Circulation of blood, which depends on a pumping and beating heart muscle, can stop during cardiac arrest. People who are not health care professionals should provide medical assistance only if they are able to do so in a way that is safe for themselves and the person who is having a health emergency. For example, they should not enter a burning building or attempt to rescue someone from a dangerous environment such as the side of a steep cliff. Without proper training or equipment, people attempting a rescue can end up among the injured.
After assessing the situation, rescuers should immediately begin emergency care, if appropriate for the situation, which may include
Maneuvers to relieve choking (for example, abdominal thrusts, also called the Heimlich maneuver)
Cardiopulmonary resuscitation (CPR) for people in cardiac arrest
Direct pressure to areas with visible bleeding
The next priority is to get medical assistance by calling for emergency medical care. In the United States, emergency medical care can be accessed by calling 911. The caller should give the dispatcher as full a description as possible of the person's condition and how the injury or illness developed. The caller should not hang up until told to do so. If several laypeople (rescuers) are present, one should call for help while another begins assessment and first aid. If only one rescuer is available, wait to call for help until after starting emergency care.
After calling 911 or the local emergency service, rescuers, when necessary, can also give people the following rescue medications:
Epinephrine in a premeasured, single-dose, intramuscular injection device (for example, EpiPen) for life-threatening allergic reactions (anaphylaxis), such as after a bee sting or eating a food a person is allergic to
Naloxone, in the nose or by intramuscular injection, if a person stops or nearly stops breathing after an opioid drug overdose (for example, heroin, oxycodone [including Oxycontin], fentanyl)
If many people are injured, the most seriously injured person should be treated first. Assessment should take less than 1 minute per injured person. In each case, the rescuer should consider whether the situation is
Life threatening
Urgent but not life threatening
Not urgent
Determining who is in most urgent need of treatment may be difficult, because someone screaming in pain may be less seriously injured than someone who cannot breathe or who is in a coma and, therefore, is quiet. Difficulty breathing and massive bleeding are life threatening, but a broken hand or foot can almost always wait for treatment, no matter how painful.
When there are many people with serious injuries and resources are limited, rescuers may need to provide treatment only to those people who rescuers believe have a chance of surviving.
When injured people are unable to convey medical information because they are confused or unconscious or because of the severity of their condition, the information should be obtained in other ways. For example, if an unconscious person is found near an empty bottle of pills, the bottle should be given to the emergency medical personnel. A description of how a person became injured and other information from bystanders, family members, or rescuers can be essential to the person's treatment.
People who do not need urgent treatment are provided reassurance and simple measures, such as having a blanket supplied and being kept calm and warm, while they wait to be treated.
To prevent the spread of blood-borne infections, rescuers should protect themselves by following universal precautions, which is an approach to preventing transmission of infection by considering all human blood and body fluids to be potentially infectious. For example, serious diseases, such as human immunodeficiency virus (HIV) infection and hepatitis B and hepatitis C (see Overview of Hepatitis), can be transmitted through blood and certain body fluids. If possible, rescuers should wear latex or nitrile examination gloves for the best protection. If gloves are not available, plastic can be used. For example, rescuers can place their hands inside plastic food storage bags or anything waterproof. Face masks and safety glasses (or face shields) and protective gowns and caps also should be worn if splashing of fluids or blood may occur.
After first aid is completed, rescuers should cleanse their skin of any contaminants. For example, they should wash their hands—including the area under the fingernails— vigorously with soap and water as soon as possible. If soap and water are not readily available, an alcohol-based hand sanitizer can be used.