This is honestly the best way I've found to explain POTS to people who don't absorb medical information well. Unfortunately, I have to portray myself as William Afton to get my point across.
We are constantly inside a springlock suit.
During the day, when we are wearing compression gear, hydrating, intaking sodium and electrolytes, taking medication, regulating our body temperature, taking breaks, eating smaller meals, managing our diet; all of those symptom management tools are metaphorically winding the springs inside the springlock suit to keep the animatronic parts coiled back.
But if we move too much, if we get hurt, if we neglect to manage our symptoms, aka not winding the springs, we flare. The springs snap back and impale us with metal from every possible location on our body, and we get stuck for an extended period of time.
My friends don't really do well with medical terminology, and we all tend to find it a bit depressing, so this metaphor seems to help. If they ask how I'm doing today and I send a picture of Springtrap, they know I'm really going through it.