Muscle weakness was without a doubt one of my most debilitating symptoms but I can say that with certainty, the intensity of the symptoms has dissipated over the course of my treatment. I'd come to learn that physical exertion would trigger the muscle weakness but not every time. I find myself riding a bike 15 miles one day with no flare up and the next day, walking down the stairs would initiate one. It really depends what is going on in your body that will determine when and how severe the muscle weakness will come on.
Normally when you tell someone who doesn't have Lyme that one of your symptoms is muscle weakness, they assume you mean that your muscles are just tired. You know, what you would normally experience after a workout. This could not be further from the truth. The best way I can describe muscle weakness with Lyme is that your body feels as if gravity has decided to make you heavier and you're constantly walking around with excessive weight on your limbs.
I first experienced muscle weakness at its prime while I was working. While at work, I would be required to lift very heavy objects. We're talking objects more than half my body weight. This was the trigger. The weakness would not manifest itself when the physical exertion started. It would usually wait about an hour. When it came on, it was bad. I would punch of work and as I walked to my Jeep, the only thoughts I had were, "Man I could use a wheel chair right about now." I'd then make the drive home and literally throw myself into my bed. I would lay in bed, close my eyes and just think about how weak I was. As I layed in bed, I was so weak, I felt that I could not even hold myself up on the bed, even though I was laying down! Gravity was just pounding me.
As this occurred time and time again, the frustration of not knowing what caused it had a huge impact on my psyche. It was such a debilitating symptoms for a 22 year old to experience. It was even more frustrating being told by doctors that all your tests are normal.
Since the diaphragm is a muscle, it too was also affected by whatever was plaguing my body. Many times it can become very difficult to breath. Your body naturally breaths involuntarily. You don't choose to breath, though you can if you wanted to, your brain has control of that. When the muscle weakness comes on, this can be very scary as you literally feel you have to take over your breathing voluntarily. I would feel when I would exhale, if I didn't willing choose to breath, my body would be deprived of oxygen. I'd somehow just stop breathing.
I have to point out that air hunger is different from weakness of the diaphragm. With air hunger, one can not catch their breath. With muscle weakness, your diaphragm feels as if it just doesn't want to contract.
The muscle weakness I experience now doesn't occur as profound as it once did. It's getting better with treatment and when it does occur, it usually happens at night while I'm sleeping. I'll end up waking up in the middle of the night with quite the surprise. It's scary because you don't want to fall back asleep but the next morning, it all clears up like it never even happened. Even without warning, the muscle weakness can come out without any indication of a trigger in sight. It's extremely random and just as quick as it can exploit itself, it can leave.
Your muscles are controlled by electrical impulses sent from nerves. Lyme is a neurotoxic bacteria. When the Lyme invades your nervous system, it can do whatever it wants to, whenever it wants to. It's only another reason why the disease is so debilitating because you can't control it or even predict when a flare up could occur.