Unlike the othe comment, this DOES sound like it could be BPPV, where something like the epley maneuver would work. Typically we would use the Semont-plus maneuver (same idea, slightly different). Or there is a fun half somersault maneuver the person could try on their own.

Bppv will be brief but intense episodes lasting seconds with lasting nausea for minutes and exasterbated by head movements. You will also see their eyes jumping or flicking (nystagmus).