I hear everybody talking about breathing. I can breathe, but I get really short of breath. I feel like I have been running a marathon. Is this likely from the MG? And if it is, why is it? What physiology is involved?
Is it that some of the breathing muscles get fatigued, and the others have to take up the slack?

Breathing requires diaphragm expansion and contraction....controlled by muscles. We don't really think that muscles aid the diaphragm, our gastrointestinal track, our heart (a muscle too) - - but it's all part of the deal!

When first dx'd, my neuro told me that MG weakness is greater closer to and within the trunk of the body. I thought that was strange since I was complaining about my arm getting weak. But after they did some strength tests...it was quite obvious the maximum weakness was proximal. I had been making adjustments (without realizing it) to compensate. (an example would be using my arms to aid my departure from a sitting position!)

When I start to breath shallowly, I know it's either time for a pill....or time to quit whatever I'm doing....or both!! There are some folks here who don't get the 'shallow' warning...and can get into some dangerous situations pretty quickly.

The way it was explained to me is that mg affects any muscle you have control over. Since you have some control over your breathing (you can hold your breath, breathe faster, etc), your lungs are affected by mg also. When I'm not doing too well, I can't even walk across a room without being short of breath. It is one of the first signs to me that I need to stop and rest!

Good luck.

I was diagnosed with heart failure several years ago. As it turned out, when my blood pressure was brought under control, my enlarged heart went back to normal size. For years I would gasp for breathe with my heart stuff. I got better from all that. Now I am really short of breathe again. The cardiologist says that it absolutely is not cardiac. I wonder how much of it was really cardiac back then.

I guess it is all part of the MG.

The diaphragm is a muscle.

diaphragm /di·a·phragm/ (diŽah-fram)
1. the musculomembranous partition separating the abdominal and thoracic cavities and serving as a major muscle aiding inhalation.

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Its not that some of the breathing muscles get fatigued.

It is the diaphragm that gets fatigued.

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