Why does my body shake when I lean up from laying down? LETS PLAY DOCTOR

[Garamonde]

I can't say I can relate to your exact problem, but I can certainly say I've felt shaking too (but it's internal and only occurs when I wake up in the middle of the night. That's the one sign that tells me my body's trying to make me throw up for some reason after shaking for some time, though a few times I've prevented it by trying to lay still with my blanket on whether it's hot or not. Not very fun) and I don't know what causes it either when I feel alright the night before. Do you feel sick or anything weird while you're shaking?