Oppressive Ghost Dreams is Nigel Wiseman’s translation of the Chines meng yan. More succinct and everyday English translation would be nightmares..
Nightmares occur in REM sleep and, in contrast to night terrors, the patient recalls disturbing dream content. Although nightmares typically cause awakening, in contrast to night terrors, they are seldom associated with increased heart rate or rapid breathing ad are generally experienced as less disturbing than sleep terrors.