How does fluid in ear cause vertigo?

Not usually: Fluid in the ear does not generally cause vertigo. I've seen patients complain of imbalance with fluid in the ear. The most common causes of vertigo are meniere's disease, migraine, benign paroxysmal positional vertigo (bppv), viral labyrinthitis, vestibular neuronitis. Fluid is not seen in the middle ear with any of these, generally. Fluid changes in the inner ear cannot be seen on exam.

Phleboliths: Phleboliths are tiny stones or particles inside the fluid-filled semicircular canals; if one of these tiny particles becomes stuck on the cilia (tiny hairs attached to nerves and sensing the fluid movement within the canals), the result is a spinning sensation (vertigo). This is one cause of vertigo. One can be taught the epley maneuvers to dislodge a phlebolith.