Alertness - decreased

Definition

Decreased alertness is a state of reduced awareness.

A coma is a state of decreased alertness from which a patient cannot be awakened. A long-term coma is called a vegetative state.

Causes

Many conditions can cause decreased alertness, including:

Chronic kidney disease
Extreme tiredness or lack of sleep
High blood sugar or low blood sugar
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:

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 (arrhythmia)
Lack of oxygen (hypoxia) from any cause
Low blood pressure (hypotension)
Low sodium levels in the blood
Severe heart failure
Severe lung diseases
Very high blood pressure

Toxins and drugs, such as:

Alcohol abuse (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 medications
Side effect of almost any medicine, such as those used to treat seizures, depression, psychosis, and other illnesses

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.

Persons with epilepsy or other seizure disorder should carry a Medic-Alert bracelet or pendant 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 doctor 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 medications 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 or blood differential
CT scan or MRI of the head
Electrocardiogram (ECG)
Electroencephalogram (EEG)
Electrolyte panel
Toxicology panel
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.

Review Date: 4/3/2011
Reviewed By: Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

This information 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. Call 911 for all medical emergencies. © 1997- 2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.