Inconsolable

Anyone having/previously have issues with LO having nightmares or night terrors? My 8-month-old has had trouble these past few nights, with the worst being last night. He woke himself up (or I guess it's possible he was still asleep) crying/screaming and even with attempting to comfort him it picked up in intensity until he was almost hoarse from screaming. He eventually did calm down after being walked and rocked, but it took a solid 5 minutes and he was inconsolable before he finally settled. This is super unlike him because he's a relatively happy baby. Anyone have any experience or insight into this?