Drowsiness refers to feeling abnormally sleepy during the day. People who are drowsy may fall asleep in inappropriate situations or at inappropriate times.

See also: Idiopathic hypersomnia

Sleepiness - during the day; Hypersomnia; Somnolence

Excessive daytime sleepiness (without a known cause) suggests that you have a significant sleep disorder. It is different from fatigue.

Depression, anxiety, stress, and boredom can all contribute to excessive sleepiness, but these conditions more typically cause fatigue and apathy.

• Having to work long hours or different shifts (nights, weekends)
• Medications (tranquilizers, sleeping pills, antihistamines)
• Medical conditions (such as hypothyroidism, hypercalcemia, and hyponatremia /hypernatremia)
• Not sleeping for long enough
• Sleep disorders (such as sleep apnea syndrome and narcolepsy)

Review Date: 06/01/2009
Reviewed By: Jeffrey Heit, MD, Internist with special emphasis on preventive health, fitness, and nutrition, Philadelphia VA Medical Center, Philadelphia, PA. 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 (www.urac.org)