Definition of myasthenia in English:



  • 1[mass noun] A condition causing abnormal weakness of certain muscles.

    • ‘He is receiving plasmapheresis as part of his treatment for myasthenia.’
    • ‘Unlike myasthenia, however, it is associated with improved strength with repeated muscle activity.’
    • ‘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.’
    • ‘Louise suffers from osteoporosis and myasthenia, a muscle weakness which means she needs to sleep for about four hours after every riding lesson.’
    1. 1.1A rare chronic autoimmune disease marked by muscular weakness without atrophy, and caused by a defect in the action of acetylcholine at neuromuscular junctions.
      • ‘The drug was first approved by the FDA as a treatment for myasthenia gravis, a chronic neuromuscular disease.’
      • ‘Patients with myasthenia gravis typically present with weakness, developing with or aggravated by exertion.’
      • ‘Congenital myasthenia gravis is rare and can be excluded by maternal and neonatal history.’
      • ‘It has been useful in treating autoimmune diseases such as myasthenia gravis.’
      • ‘Doctors said a recent checkup indicated he was suffering from an auto-immune disorder called myasthenia gravis, symptoms of which began appearing at the end of last month.’


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