BPPV (benign paroxysmal positional vertigo) - tiny crystals in the balance organ of the inner ear shifting out of place, causing brief intense spinning triggered by head movement such as rolling over in bed.
A viral illness affecting the balance nerve, producing a prolonged episode of severe dizziness that typically improves over days to weeks as the brain adjusts.
Meniere's disease causing recurring attacks of vertigo lasting between twenty minutes and several hours, accompanied by ringing in the ear and fluctuating hearing loss.
Less commonly, a central cause arising from the brain or brainstem - important to exclude in patients with accompanying neurological symptoms such as double vision, weakness, or difficulty speaking.
Bhattacharyya N et al. Clinical Practice Guideline: Benign Paroxysmal Positional Vertigo. Otolaryngol Head Neck Surg. 2017;156(3 Suppl):S1-S47. NICE guideline CG124. 2014.