Decreased alertness is a state of reduced awareness.
A coma is a state of decreased alertness from which a person cannot be awakened. A long-term coma is called a vegetative state.
Stuporous; Mental status - decreased; Loss of alertness; Decreased consciousness; Changes in consciousness; Obtundation; Coma; Unresponsiveness
Many conditions can cause decreased alertness, including:
Brain disorders or injury, such as:
Injury or accidents, such as:
Heart or breathing problems, such as:
Toxins and drugs, such as:
Get medical help for any decrease in consciousness, even when it is due to alcohol intoxication, fainting, or a seizure disorder that has already been diagnosed.
People with epilepsy or other seizure disorders should wear a medical ID bracelet or necklace describing their condition. They should avoid situations that have triggered a seizure in the past.
When to Contact a Medical Professional
Get medical help if someone has decreased alertness that cannot be explained. Call your local emergency number (such as 911) if normal alertness does not return quickly.
What to Expect at Your Office Visit
Most often, a person with decreased consciousness will be evaluated in an emergency room.
The health care provider will perform a physical examination. The exam will include a detailed look at the heart, breathing, and nervous system.
The health care team will ask questions about the person's medical history and symptoms, including:
Tests that may be done include:
Treatment depends on the cause of the decreased alertness. How well a person does depends on the cause of the condition.
The longer the person has had decreased alertness, the worse the outcome.
Bassin BS, Cooke JL. Depressed consciousness and coma. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 16.
Bassin BS, Cooke JL, Barsan WG. Altered mental status and coma. In: Adams JG, ed. Emergency Medicine: Clinical Essentials. 2nd ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 94.
Wilber ST, Ondrejka JE. Altered mental status and delirium. Emerg Med Clin North Am. 2016;34(3):649-665. PMID: 27475019 www.ncbi.nlm.nih.gov/pubmed/27475019.
Review Date: 5/15/2017
Reviewed By: Amit M. Shelat, DO, FACP, Attending Neurologist and Assistant Professor of Clinical Neurology, SUNY Stony Brook, School of Medicine, Stony Brook, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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