Myasthenia Gravis terminology

dedicated to raising awareness of Myasthenia Gravis.

When talking about myasthenia gravis it helps to know the vocabulary, the terms used by others, the words recognized by doctors that trigger their thinking in certain ways.

Many health care professionals have MG in their medical school class. Neurologists may have studied MG more, but since it is considered a rare disease, many still may never see a patient with myasthenia gravis. And since there are other diseases that mimic myasthenia gravis, physicians are thorough in their search for conclusive diagnosis.

Learning the language

Being familiar with the terminologies is helpful when talking with someone in the medical profession. We want our words to make sense to the health professional in the same way that when they speak to us we want to understand what they are telling us.

We can contribute to our own health through understanding if we are somewhat aware of what words mean. There are a number of words most commonly used in conversation. When you do not understand, stop the conversation and get clarification.

Myasthenia Gravis

MG is generally known to affect any of the muscles that you control voluntarily, (eyes, mouth throat, limbs) as well as chest muscles, and the diaphragm, which is both voluntary and involuntary.

There are several types of myasthenia gravis. (MG Type)

Some commonly used terms

  • Myasthenia Gravis: from Latin and Greek: grave or serious muscle weakness
  • Exacerbation: also known as flare-up when symptoms become more severe and/or increase in frequency
  • (MG Type) Bulbar weakness: when weakness and fatigue in the neck and jaw occur early in MG
  • (MG Type) Congenital myasthenia gravis: when the disruption at the synapse happens because of genetic defects, not because of antibodies
  • (MG Type) Generalized myasthenia gravis:  when MG is affecting multiple muscle groups throughout the body
  • (MG Type) Juvenile myasthenia gravis: a rare form of MG, expressed by ocular muscle weakness or generalized weakness, with onset before 18 years of age.
  • (MG Type) Muscle-specific tyrosine kinase (MuSKmyasthenia gravis: affects mainly the facial bulbar muscles. It is noted for a unique disease development from more common MG types
  • (MG Type) Ocular myasthenia gravis: when only the muscles that move the eyes and eyelids are affected
  • (MG Type) Transient neonatal myasthenia gravis: when MG is transmitted from an affected mother to her fetus. The symptoms in the baby normally disappear two to three months after birth.
  • Myasthenic Crisis: complication of MG characterized by worsening of muscle weakness resulting in respiratory failure; can be life threatening
  • Neuromuscular junction: synapse, between a motor neuron nerve terminal and its muscle fiber, where communication between motor nerves and muscle fibers happens that facilitates voluntary movement.
  • Synapse: where electrical signals turn into chemical information, which is then conveyed between neurons…
  • Simplistically: Brain message>nerve>synapse>muscle
  • and the muscle does not get the message because the communication in the synapse doesn’t happen.
  • Thymectomy: surgical removal of the thymus gland
  • Thymoma: Tumor of the thymus gland.
  • Thymus: A flat, H-shaped gland lying mainly behind the breastbone (sternum) and in front of the heart. It is important for immune system development early in life, and shrinks with aging.
  • Remission: symptoms disappear completely for some time even without treatment


Commonly recognized among myasthenia patients as one of the first areas where they observe weakness. However, not all myasthenia cases begin with eye muscle issues.

  • Ocular myasthenia: characterized by variable weakness of the muscles of the eyelids and eye movements. This leads to droopy eyelids (ptosis), double vision (diplopia), or both.
  • Diplopia: Double vision, horizontal or vertical, in various degrees. Vision may improve with one eye closed
  • Ptosis: Drooping or falling of one or both eyelids that may include variations. Upper eyelid muscle weakness can increase as muscles tire.


  • Dysphonia: voice disorder
  • Facial expressions: around the mouth and eyes


  • Dysarthria: slurred or impaired speech
  • Dysphagia: difficulty swallowing


  • Muscle weakness: Hand and finger weakness
  • Proximal limb weakness: Limb weakness
  • Muscle weakness: Trouble walking


  • Respiratory failure is a condition of extreme muscle weakness, particularly of the diaphragm and chest muscles that support breathing. Breathing may become shallow or ineffective. When you have trouble breathing, get to emergency, letting the staff know you have myasthenia gravis and are in crisis. A ventilator may be required

As part of our campaign of awareness, we identify commonly recognized symptoms of myasthenia gravis. We speak of symptoms associated with myasthenia gravis, BUT the presence of any of these symptoms does not mean that anyone has a specific disorder. This site does not diagnose nor suggest diagnosis or treatment

When browsing for additional information, print out the fact sheets – you can make notes on them later. Or create your own.

The National Institute of Neurological Disorders and Stroke invite you to print out their FACT SHEET from their website. It is quite helpful in explaining terms in their context:

Dig deeper into the world of Myasthenia Gravis on this NIH site. Begin to zero in on what specifically you can relate to and make note of the website URLs, the words used, the sources of information for discussion with your doctor.

LOOKING FOR THE COMMENT SECTIONS? Click titles of blog articles and you will go to each post separately, where comment section is at the bottom. Thank you.

Watch our right side bar to see most recent posts about many aspects of Myasthenia Gravis.

others can learn by reading what you have discovered… a site solely for awareness of Myasthenia Gravis.

Myasthenia Gravis terminology (c) 2021 Judith Allen Shone

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Iris represents wisdom and hope


Author: jas

Caregiver - author - MG survivor 67 years Sites where you find out about me:

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