Definition of myasthenia in English:

Share this entry


Pronunciation: /ˌmʌɪəsˈθiːnɪə/


[mass noun]
1A condition causing abnormal weakness of certain muscles.
Example sentences
  • Louise suffers from osteoporosis and myasthenia, a muscle weakness which means she needs to sleep for about four hours after every riding lesson.
  • Surgical removal of the thymus gland is performed in patients with a thymoma and can also help some other patients, especially those who develop myasthenia before the age of about 45.
  • Unlike myasthenia, however, it is associated with improved strength with repeated muscle activity.
1.1 (in full myasthenia gravis /ˈɡrɑːvɪs/ /ˈɡravɪs/) A rare chronic autoimmune disease marked by muscular weakness without atrophy, and caused by a defect in the action of acetylcholine at neuromuscular junctions.
Example sentences
  • It has been useful in treating autoimmune diseases such as myasthenia gravis.
  • The drug was first approved by the FDA as a treatment for myasthenia gravis, a chronic neuromuscular disease.
  • Congenital myasthenia gravis is rare and can be excluded by maternal and neonatal history.


Mid 19th century: modern Latin, from Greek mus 'muscle' + asthenia.

For editors and proofreaders

Line breaks: my¦as|the¦nia

Share this entry

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.