The first priority is to assess a person's airway, breathing, and circulation (the ABCs). A problem in any of these areas may be fatal if not corrected. The airway (A), which is the passage through which air travels to the lungs, can become blocked (for example, by choking on a piece of food). Many disorders and injuries can make breathing (B) difficult. Circulation (C) of blood, which depends on a pumping and beating heart muscle, can stop during cardiac arrest, in which case cardiopulmonary resuscitation (CPR) is necessary.
The next priority is to get medical assistance by calling for emergency medical care, except when people experience:
When a person's heart stops or a person is choking, treatment should be started before calling for help. In the United States, emergency medical care can be accessed by calling 911. The caller should give the dispatcher a full description 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 lay people (rescuers) are present, one should call for help while another begins assessment and first aid.
After calling for medical assistance, the ABCs are corrected before any other treatment is started. Cardiopulmonary resuscitation (CPR—see First Aid: First-Aid Treatment) is provided, if necessary.
If many people are injured, the most seriously injured person should be treated first. 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. 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, or not urgent. 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. After these steps have been taken, reassurance and simple measures, such as supplying a blanket and keeping the person calm and warm, can provide comfort.
Serious diseases, such as human immunodeficiency virus (HIV) infection and hepatitis B and C, can be transmitted through blood. Rescuers should avoid contact with blood from wounds, especially the blood of strangers whose medical history is unknown. Latex or nitrile examination gloves afford 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. If contaminated with blood, the hands—including the area under the fingernails—should be washed vigorously with soap and water or a mild solution of bleach (about 1 tablespoon of bleach per quart of water, or about 15 milliliters of bleach per liter of water) as soon as possible. If neither is readily available, an alcohol-based hand sanitizer can be used. Contact with saliva and urine is much less likely to result in disease transmission than is contact with blood.
Last full review/revision March 2013 by Amy H. Kaji, MD, PhD