If you don’t get dizzy when lying flat on your back and get dizzy when you move from side to side, you may have otolithiasis. Otolithiasis is also known as benign paroxysmal positional vertigo, which refers to short paroxysmal episodes of vertigo and nystagmus that occur when the head moves rapidly to a particular head position. Normally otoliths are attached to the otolithic membrane, and when some pathogenic factor causes the otoliths to detach, these dislodged otoliths swim in a fluid called endolymph in the inner ear. When there is a change in the body’s head position, including side-to-side movement, and these semicircular canals change with it, the submerged otoliths move with the fluid, which stimulates the semicircular hair cells and causes the body to experience intense vertigo. The duration will usually be short, lasting a few seconds or minutes, and can be periodically aggravated or relieved, with varying lengths of illness.