Site Map

Unconsciousness - first aid

Loss of consciousness - first aid; Coma - first aid; Mental status change; Altered mental status; Syncope - first aid; Faint - first aid 

Unconsciousness is when a person is unable to respond to people and activities. Health care providers often call this a coma or being in a comatose state.

Other changes in awareness can occur without becoming unconscious. These are called altered mental status or changed mental status. They include sudden confusion, disorientation, or stupor.

Unconsciousness or any other sudden unexplained change in mental status must be treated as a medical emergency.

Presentation

Recovery position - series

Causes

Unconsciousness can be caused by nearly any major illness or injury. It can also be caused by substance (medicine or drug) and alcohol use. Choking on an object can result in unconsciousness as well.

Brief unconsciousness (or fainting) is often a result from dehydration, low blood sugar, or temporary low blood pressure. It can also be caused by serious heart or nervous system problems. A provider can determine if the affected person needs tests to diagnose their fainting.

Other causes of fainting include straining during a bowel movement or urination, coughing very hard, breathing very fast (hyperventilating), or vasovagal syncope.

Symptoms

The person will be unresponsive (does not respond to activity, touch, sound, or other stimulation).

The following symptoms may occur after a person has been unconscious:

If the person is unconscious from choking, symptoms may include:

Being asleep is not the same as being unconscious. A sleeping person will respond to loud noises or gentle shaking. An unconscious person will not.

First Aid

If someone is awake but less alert than usual, ask a few simple questions, such as:

Wrong answers or not being able to answer the question suggest a change in mental status.

If a person is unconscious or has a change in mental status, follow these first aid steps:

Call or tell someone to call 911 or the local emergency number.

If the person is unconscious from choking:

Do Not

When to Contact a Medical Professional

Call 911 or the local emergency number if the person is unconscious and:

Call 911 or the local emergency number if the person regains consciousness, but:

Prevention

To prevent becoming unconscious or fainting:

If you have a medical condition, such as diabetes, always wear a medical alert necklace or bracelet.

Related Information

Concussion in adults - what to ask your doctor
Concussion in children - what to ask your doctor
Concussion in children - discharge
Concussion in adults - discharge
Preventing head injuries in children

References

Hewett Brumberg EK, Douma MJ, Alibertis K, et al. American Heart Association and American Red Cross. 2024 American Heart Association and American Red Cross guidelines for first aid. Circulation. 2024;150(24):e519-e579. PMID: 39540278 pubmed.ncbi.nlm.nih.gov/39540278/.

Lei C, Smith C. Depressed consciousness and coma. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 12.

Perman SM, Elmer J, Maciel CB, et al. 2023 American Heart Association focused update on adult advanced cardiovascular life support: An update to the American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2023;149(5):e254-e273. PMID: 38108133 pubmed.ncbi.nlm.nih.gov/ 38108133/.

Probst M. Syncope. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 11.

BACK TO TOP

Review Date: 1/8/2025  

Reviewed By: Jesse Borke, MD, CPE, FAAEM, FACEP, Attending Physician at Kaiser Permanente, Orange County, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

ADAM Quality Logo
Health Content Provider
06/01/2028

A.D.A.M., Inc. is certified by URAC, for Health Content Provider (www.urac.org). URAC's certification program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2025 A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.