Alertness - decreased

  • Definition
    • 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.

  • Alternative Names
    • Stuporous; Mental status - decreased; Loss of alertness; Decreased consciousness; Changes in consciousness; Obtundation; Coma; Unresponsiveness

  • Causes
  • Home Care
    • 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.

      See the article on seizures for tips on how to care for a person who is having a seizure.

      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:

      Time pattern

      • When did the decreased alertness happen?
      • How long did it last?
      • Has it ever happened before? If so, how many times?
      • Did the person behave the same way during past episodes?

      Medical history

      • Does the person have epilepsy or a seizure disorder?
      • Does the person have diabetes?
      • Has the person been sleeping well?
      • Has there been a recent head injury?


      • What medicines does the person take?
      • Does the person use alcohol or drugs on a regular basis?
      • What other symptoms are present?

      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.

  • References
    • 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 Mosby; 2013: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.

      Lank PM, Kusin S. Ethanol and opioid intoxication and withdrawal. In: Adams JG, ed. Emergency Medicine: Clinical Essentials. 2nd ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 154.

      Lennihan L. Delirium and Confusion. In: Rowland LP, Pedley TA, eds. Merritt's Neurology. 12th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2009:chap 2.

      MacNeill EM, Vashist S. Approach to syncope and altered mental status. Ped Clin N Am. 2013;60(5):1083-1106.