Definition of Alertness - decreased:

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.

See also:

• Delirium
• Dementia

Common 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:

• Dementia or Alzheimer's disease
• Head trauma
• Seizure
• Stroke

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