BPPV is caused by a problem with the inner ear. Calcium crystals called canaliths can end up in the semi-circular canals. If these crystals become dislodged and move around, they can cause the sensation that the world is spinning or moving, also known as vertigo. The Epley manoeuvre, however, can dislodge these crystals and remove them from the semi-circular canals.

The Epley manoeuvre is often effective for many patients with BPPV, especially in cases where certain head movements seem to trigger vertigo. Many people say their symptoms are relieved immediately after the manoeuvre, though some may have mild symptoms for a few weeks. The manoeuvre is generally safe for most people to use.