Quantcast
Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Medical
  • Scrabble
  • Spanish Central
  • Learner's Dictionary

Medical Dictionary

polio

play
noun po·lio \ˈpō-lē-ˌō\

Medical Definition of polio

  1. :  an infectious disease especially of young children that is caused by the poliovirus Individuals infected with the poliovirus are often asymptomatic. In approximately 25% of cases, polio presents as a mild to moderate illness marked by headache, fever, sore throat, vomiting, diarrhea, and fatigue. Polio affects the central nervous system only infrequently with inflammation and sometimes destruction of the motor neurons in the gray matter of the spinal cord and brain stem. Central nervous system involvement results in temporary or permanent muscle weakness or flaccid paralysis of muscles especially of the limbs and typically the legs. Polio may become life-threatening when paralysis affects the muscles involved in breathing and swallowing. <Thanks to the Salk and Sabin vaccines, the specter of crippling polio that once made summers an apprehensive time for Americans has long since passed.—People Weekly, 17 Sept. 1984> <While the last case of naturally occurring polio in the United States was in 1979, the disease remains prevalent in other areas of the world.—Evan Johnson, The Addison County (Vermont) Independent, 21 Aug. 2014>—called also , ; see post-polio syndrome




Learn More about polio


Seen and Heard

What made you want to look up polio? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

to defraud especially of money

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

image567572573

Which of these is a synonym of unctuous?

oily prompt maudlin angry
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ