Otoliths are clinically known as benign paroxysmal positional vertigo, which refers to brief paroxysmal episodes of vertigo and nystagmus that occur when the head moves rapidly to a specific head position. The human ear is divided into the outer ear, middle ear and inner ear. In the inner ear, there are three semicircular canals called semicircular canals and two sacs (ellipsoidal sac and balloon sac) that constitute the balance organ of the human ear. The otoliths are mainly calcium carbonate crystals that are involved in controlling the body’s balance. When the otolith is dislodged for some reason, the otolith floats in the inner ear and when the floating otolith enters the semicircular canal and touches the receptors in the semicircular canal in certain head positions, vertigo and nystagmus can occur. The disease occurs mostly in middle-aged people, slightly more in women than in men, and it occurs suddenly when changing head position, such as when sitting up in the prone position, or when lying down suddenly in the sitting position, or when bending down, lowering, tilting, or turning the head left or right, with a sudden onset of strong rotational vertigo, usually lasting within 30 seconds and up to 1 minute, accompanied by nystagmus (rapid nystagmus), nausea and vomiting. After the vertigo stops, there may be a feeling of head heaviness, floating, unsteadiness, and discomfort when moving the head. Most patients with otoliths have an unknown cause, i.e. primary otoliths, or secondary to vestibular neuritis, Meniere’s disease, sudden deafness, viral labyrinthitis, migraine, head trauma, after middle or inner ear surgery, after cochlear implantation, otosclerosis, inner ear malformation, chronic middle ear mastoiditis, ototoxic drugs, etc. In summary, otoliths are mainly caused by various causes of otolith dislodgement. When there are unexplained recurrent episodes of transient vertigo and nystagmus, prompt medical attention is required.