bitter, hot temper, irritable, nervous
癇 centers on an irritable, nervous state that can flare into a hot temper or bitter feeling. The convulsion reading ひきつけ extends this to a physical nervous spasm.
癇 combines the sickness radical 疒 with 閒, which likely contributes the sound カン and may suggest a confined, agitated state. The exact historical development is uncertain.
The sickness enclosure 疒 wraps around 閒, which looks like a gate 門 with a sun 日 inside. Picture a person trapped behind a gate in the hot sun, becoming increasingly irritable and bitter until their temper boils over.
For カン, imagine a can of bitter, hot-tempered nerves shaking under pressure: can -> カン, and the can is about to burst from the irritable heat inside.
epilepsy; epileptic fit
temper; irritability; fit of anger; tantrum (esp. of children); temper tantrum
temper; nerves
Jacksonian epilepsy
photosensitive epilepsy
traumatic epilepsy
eclampsia
preeclampsia
to irritate; to offend; to provoke; to get on one's nerves
irritable
irritability; peevishness; irascibility; hot temper
short temper
to lose one's temper; to throw a tantrum; to fly into a rage
hot-tempered person
(an) epileptic