The 5-minute crash: When my MG symptoms change without warning

Note: This column describes the author’s own experiences with intravenous immunoglobulin (IVIG) infusions. Not everyone will have the same response to treatment. Consult your doctor before starting or stopping a therapy.

One of the most disorienting parts of living with myasthenia gravis (MG) is how quickly everything can change. I can move from steady to struggling in the span of a few breaths. These moments are not typically dramatic or loud. They are quiet shifts that make me stop mid-sentence or sit down before my legs decide for me.

For a long time, these crashes felt random. They felt like my body was betraying me without warning, and they were frustrating as all heck. Over time, I learned that even the sudden moments often have patterns behind them. They are tied to internal rhythms, hidden triggers, and the way MG responds to small changes inside my body.

One of the most confusing versions of this happens after my intravenous immunoglobulin (IVIG) infusions. There is a window, usually a day or two after treatment, when I feel near euphoric. My muscles feel lighter. My breathing feels easier. My energy feels like it belongs to someone who does not have MG. Because that feeling is rare, I want to make the most of every second of it.

So I do everything I have been putting off. I clean, organize, cook meals, show my husband some attention, and try to live the life I miss when my symptoms are louder. It feels like freedom and possibility. It feels like getting my life back.

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The coming crash

But I start the day post-infusion in a sprint instead of a carefully paced marathon. IVIG helps, but it does not erase the underlying reality of MG. The crash that follows is not always dramatic. Sometimes it is a heaviness in my jaw, a wave of fatigue, or air hunger that seemingly arrives without warning. I know better, and the air brakes this quick crash applies are always a reminder to pace my activity better, regardless of how amazing I feel in the moment. Sometimes the onset of symptoms after treatment is not a crash at all, but simply my body reminding me that feeling better does not mean I can outrun the condition.

Other times, the crash is sharper and leaves no room for doubt. I can be walking, talking, or laughing when my muscles suddenly feel twice as heavy, my breathing shifts, my eyelids start to droop, and my legs feel like wet noodles. It is the kind of change that makes me pause and think, “WTF? Where did THAT come from?!”

These moments used to terrify me. Now, they frustrate me even though I understand that they are often tied to things I cannot see, such as a night of poor sleep, a hormone shift, or a lingering immune response. Even a prolonged elevated heart rate can set things off for me. If my heart rate stays above 110 beats per minute for too long, my diaphragm begins to fatigue and my breathing becomes shallow. I learned this through trial and error, with the help of a smartwatch that quietly tracks what my body does not always tell me.

The hardest part is that these internal triggers, especially emotional ones, do not always feel connected to what I am doing. I can be sitting still when the shift happens. I can be resting, happy, calm, things that typically don’t elicit a cortisol spike or dump that can trigger symptoms. But as we know, MG is fickle and does what it wants, like not waiting for a stressful moment or a busy day to make itself the center of attention. Sometimes the body simply decides it is done, and the symptoms follow.

Understanding these patterns, even when they are inconsistent, has changed the way I respond to them. I have learned to slow down after IVIG instead of racing through the good hours. I have learned to pay attention to my heart rate before my breathing changes. I have learned to rest before the heaviness becomes a full crash.

These moments still catch me off guard, but they no longer feel like failures. They are part of the landscape of MG, shaped by rhythms I cannot always see, but can learn to respect. And in that respect, there is a kind of steadiness. Not in my symptoms, but in the way I move through them.

Note: Myasthenia Gravis News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website. The opinions expressed in this column are not those of Myasthenia Gravis News or its parent company, Bionews, and are intended to spark discussion about issues pertaining to myasthenia gravis.