Friday, May 29, 2015

Table of Contents


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

See also: Dementia, for more information about chronic or long-term confusion.

Alternative Names

Disorientation; Thinking - unclear; Thoughts - cloudy


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. It may be associated with delirium or dementia.

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

Some confused people may have strange or unusual behavior or may act aggressively.

Common Causes
  • Alcohol intoxication
  • Brain tumor
  • Concussion
  • Fever
  • Fluid and electrolyte imbalance
  • Head trauma or head injury
  • Illness in an elderly person
  • Illness in a person with existing neurological disease such as a stroke
  • 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)

Review Date: 02/06/2010
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Luc Jasmin, MD, PhD, Department of Neurosurgery at Cedars-Sinai Medical Center, Los Angeles, CA, and Department of Anatomy at UCSF, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (