I think I would separate nightmares (horror/death/being chased/night terrors) from bad dreams (embarrassed/uncomfortable/worry/fret/didn't enjoy). We sometimes

I think I would separate nightmares (horror/death/being chased/night terrors) from bad dreams (embarrassed/uncomfortable/worry/fret/didn't enjoy). We sometimes use the term _nightmares_ to describe both, but only the former causes a cortisol reaction (in the article).. the latter, which would include worrying about bad sleep or bad dreams doesn't cause the same response. How do you know it caused a cortisol reaction? - Your heart is pounding, you're probably awake and probably have a hard time getting back to sleep. Your sleep tracker will show it too (if you have a ring or watch, your heart rate will visibly jump into your exercise range). Worrying about sleep/lack thereof/bad dreams sucks, but it's not the same as nightmares. Worth also mentioning - not everyone experiences/remembers dreams (which sounds amazing)