Hi Ann. There have been a couple of times that my husband has seen swelling as an indicator of an episode, but it's very subtle and hard to spot (sometimes in the legs, feet & neck, and once around the eyes).
However, for most of my husband's episodes he gets very little to no swelling until after IV fluids are administered. He does not experience any bouts or periods of chronic swelling as a precurser.
Instead, my husband experiences these precurser symptoms that vary depending how far the episode has progressed: dizziness, nausea, vomitting, elevated heart rate, fatigue and shortness of breath. Most symptoms put us on alert to start monitoring his blood, but as soon as he gets the elevated heart rate and/or shortness of breath, we head to the ER with our documents (and we alert our specialist that we are having an episode as he often advocates for us in the ER).