It's a question I've been asked many times in the past 26 years. I've been asked this by nurses, doctors, family, friends, and strangers. While I don't think that my actual symptoms have changed that much, the words and images I use to describe them over time have.
As a child I associated hypoglycemia with feelings like "weak, shaky and tired". It was a very distinct feeling; one where I wanted to eat and eat and eat and then sleep until I felt better. I knew that feeling, but putting it in words was difficult. I used the words I had in my verbal arsenal. (A sentence which, as a child, would have been phrased "I used the words I knew." I love being a grown-up with a thesaurus.)
Fast forward to adulthood: descriptions and metaphors aplenty.
They come in stages, those lows. I might feel a little loopy, hyper, or energetic - which then transitions to feeling a bit like I'm swimming through the air around me. My body vibrates. As I continue to drop (and this ended up being my answer to the above question, the last time I was asked it), it begins to feel similar to being drunk, minus the fun part. In my mind, I know exactly what's going on and what I need to do, but I often can't get my body to follow through with those actions, or my mouth to form the words my mind intends. I'm lucky to get out a short, staccato sentence: "I need juice". My brain sounds the alarm, screaming "YOU NEED SUGAR RIGHT NOW!!!"; it pleads with me to go eat the kitchen, if only my motor skills would show up for duty.
I know what I need to do and say, but my physical self can't translate it.
And I know I will be fine - once that parachute catches some air.