Panic attacks suck. Rationality goes out of the window. "This is it. I'm going to die."
For me, stress plus a sudden-onset painful physical trigger usually brings them on. The painful trigger can be anything from a muscle sprain to a really bad stomach ache (we're talking "I now think I might have some idea what period cramps are like and I don't have a womb" kind of pain levels here.)
Even knowing about previous experiences doesn't always help. That nagging thought that you're going to die while feeling terrible in a stressful situation.
Ironically, I've wished I was dead many times, but during a panic attack, suddenly survival instinct is the one ringing the alarm bells. WTF brain.
Passed out in a hospital during one of them. Pectoral pain + Stressful day at work = Must be having a heart attack and going to die. Nope. Just a sprained pec and a panic attack.