Confusion is the inability to think with your usual speed or clarity, including feeling disoriented and having difficulty paying attention, remembering, and making decisions.

Confusion may come on quickly or slowly over time, depending on the cause. Many times, confusion is temporary. Other times it is permanent and not curable.

Confusion is more common in the elderly, and often occurs during a hospital stay.

Some confused people may act aggressively.

• Alcohol intoxication
• Brain tumor
• Concussion
• Fever
• Fluid and electrolyte imbalance
• Head trauma or head injury
• Illness in an elderly person
• Infections
• Lack of sleep (sleep deprivation)
• Low blood sugar
• Low levels of oxygen (for example, from chronic lung disorders)
• Medications
• Nutritional deficiencies, especially niacin, thiamine, vitamin C, or vitamin B12
• Seizures
• Sudden drop in body temperature (hypothermia)

A good way to find out if someone is confused is to ask the person his or her name, age, and the date. If they are unsure or answer incorrectly, they are confused.

A confused person should not be left alone. For safety, the person may need physical restraints.

To help a confused person:

• Always introduce yourself, no matter how well the person once knew you.
• Often remind the person of his or her location.
• Place a calendar and clock near the person.
• Talk about current events and plans for the day.
• Try to keep the surroundings calm, quiet, and peaceful.

For sudden confusion due to low blood sugar (for example, from diabetes medication), the person should drink a sweet drink or eat a sweet snack. If the confusion lasts longer than 10 minutes, call the doctor.

Call 911 if:

• Confusion has come on suddenly or there are other symptoms such as:
  • Cold or clammy skin
  • Dizziness or feeling faint
  • Fast pulse
  • Fever
  • Headache
  • Slow or rapid breathing
  • Uncontrolled shivering
• Confusion has come on suddenly in someone with diabetes.
• Confusion came on after a head injury.
• The person becomes unconscious at any time.

If you have been experiencing confusion, call for an appointment with your doctor.

The doctor will do a physical examination and ask questions such as:

• Does the person get days and nights mixed up? Is he or she awake during the usual sleep time?
• Does the person have trouble recognizing people?
• Does the person know where he or she is?
• Does he or she know the date and time?
• Can the person answer questions correctly?
• Is the person always confused?
• Are there many episodes of confusion?
• Is the confusion quickly getting worse?
• Does the confusion come and go?
• Has there been any recent illness?
• Has there been a recent head injury?
• Is the person diabetic?
• Does the person have COPD, chronic bronchitis, or a similar lung disorder?
• What medications is the person taking?
• Has there been any exposure to other drugs or alcohol?

Tests may include:

• Brain and nervous system (neurologic) tests
• Cognitive tests
• MRI of the head
• Blood and urine tests
• EEG

• Don't drink too much alcohol.
• Eat a balanced diet with plenty of vitamins and minerals.
• Get enough sleep.
• Keep careful control of your blood sugar if you have diabetes.
• Quit smoking, which puts you at greater risk for lung diseases.

Leclerc S, Lassonde M, Delaney J S et al. Recommendations for grading of concussion in athletes. Sports Med. 2001; 31: 629-636.

Bazakis AM, Kunzler C. Altered Mental Status Due to Metabolic or Endocrine Disorders. Emer Med Clinics of North America. 2005; 23(3): 901-908.

Biem J. Out of the cold: management of hypothermia and frostbite. CMAJ. 2003; 168(3): 305-311.