In some cases, if certain muscles are affected, myasthenic patients can experience a myasthenic crisis, which is a life-threatening manifestation of the disease; an example of this might be a decreased function of the muscles that control breathing.

还有一些情况，如果某些肌肉被影响，重症肌无力患者发生肌无力危象，这会危及生命：如呼吸肌的功能减弱。