A nightmare is a dream that occurs during sleep that brings out strong feelings of fear, terror, distress, or anxiety. Nightmares usually happen in the second part of the night and wake up the sleeper, who is able to remember the content of the dream.

See also:

• Generalized anxiety disorder
• Night terror
• Post-traumatic stress disorder
• Sleep disorders

Dreams - bad; Bad dreams

Nightmares tend to be more common among children and become less frequent toward adulthood. About 50% of adults have occasional nightmares, women more often than men.

Anxiety and stress are the most common causes of nightmares. A major life event occurs before the nightmare in some cases.

Other causes of nightmares include:

• Abrupt alcohol withdrawal
• Breathing disorder in sleep (sleep apnea)
• Death of a loved one (bereavement)
• Excessive alcohol consumption
• Illness with a fever
• Recent withdrawal from a drug, such as sleeping pills
• Side effect of a drug
• Sleep disorder (for example, narcolepsy or sleep terror disorder)
• Eating just before going to bed, which raises the body's metabolism and brain activity

Review Date: 02/22/2010
Reviewed By: David B. Merrill, MD, Assistant Clinical Professor of Psychiatry, Department of Psychiatry, Columbia University Medical Center, New York, NY. 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 (www.urac.org)