Decreased alertness is a state of reduced awareness and is often a serious condition.
A coma is the most severe 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.
Get medical help if someone has decreased alertness that cannot be explained. Call 911 or the local emergency number if normal alertness does not return quickly.
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.
Berger JR, Price R. Stupor and coma. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 5.
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.
Reviewed By: Joseph V. Campellone, MD, Department of Neurology, Cooper Medical School of Rowan University, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.