What are night sweats?

Night sweats are drenching sweats that soak clothes and bedding and disturb sleep. Night sweats occur when blood vessels expand, causing increased blood flow, and then contract. This causes a sudden wave of heat that spreads throughout the body, followed by sweating, reddening of the skin, and rapid heartbeat. Often, the night sweat is followed by a cold chill.

Last reviewed by a Cleveland Clinic medical professional on 06/29/2017.


  • National Cancer Institute. Hot Flashes and Night Sweats. Patient Version Accessed 6/1/2017.
  • North American Menopause Society. Menopause 101: A Primer for the Perimenopausal Accessed 6/1/2017.
  • Viera AJ, Bond MM, Yates SW. Diagnosing Night Sweats. American Academy of Family Physicians. Am Fam Physician 2003;67:1019-24.

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