Decreased alertness
Stuporous; Mental status - decreased; Loss of alertness; Decreased consciousness; Changes in consciousness; Obtundation; Coma; UnresponsivenessDecreased 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.
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Causes
Many conditions can cause decreased alertness, including:
- Chronic kidney disease
- Extreme tiredness or lack of sleep
- High blood sugar or low blood sugar
- High or low blood sodium concentration
- Infection that is severe or involves the brain
- Liver failure
- Thyroid conditions that cause low thyroid hormone levels or very high thyroid hormone levels
Brain disorders or injury, such as:
- Dementia or Alzheimer disease (advanced cases)
- Head trauma (moderate to severe cases)
- Seizure
- Stroke (usually when the stroke is either massive or has destroyed certain areas of the brain such as the brainstem or thalamus)
- Infections that affect the brain, such as meningitis or encephalitis
Injury or accidents, such as:
- Diving accidents and near drowning
- Heat stroke
- Very low body temperature (hypothermia)
Heart or breathing problems, such as:
- Abnormal heart rhythm
- Lack of oxygen from any cause
- Low blood pressure
- Severe heart failure
- Severe lung diseases
- Very high blood pressure
Toxins and drugs, such as:
- Alcohol use (binge drinking or damage from long-term alcohol use)
- Exposure to heavy metals, hydrocarbons, or toxic gases
- Overuse of drugs such as opiates, narcotics, sedatives, and anti-anxiety or seizure medicines
- Side effect of almost any medicine, such as those used to treat seizures, depression, psychosis, and other illnesses
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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.
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.
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When to Contact a Medical Professional
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.
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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?
Other
- 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:
- Chest x-ray
- Complete blood count (CBC) or blood differential
- CT scan or MRI of the head
- Oxygen level (pulse oximetry or blood gas)
- Electrocardiogram (ECG)
- Electroencephalogram (EEG)
- Metabolic panel and liver function tests
- Toxicology panel and alcohol level
- Urinalysis
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
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.