Vertigo is a Symptom, Not a Diagnosis, and it’s Sometimes Caused by Loose Rocks Inside Your Head

I have written and spoken about this disease more than once…

I often hear patients speak of vertigo as if it were some brilliant diagnosis made by a genius emergency room doctor. Just because it’s a foreign word, that doesn’t make it any more clever than if they’d been told they were dizzy.

In my native Sweden there seems to be a domestic lay word for almost every disease. The runner up prize in my book goes to FÖNSTERTITTARSJUKAN, “The Window Shoppers Disease”, which we call intermittent claudication, usually caused by poor blood flow to the legs (people feeel better if they stand still for a while, for example pretending to look in a store window) but occasionally we get tricked and the symptom can be caused by pressure on the spinal cord from disc disease.

I absolutely love the number one word on my Swedish Disease Names list: The word they use for the most common cause of true vertigo, “Benign Positional Vertigo” or BPV. The Swedish word is KRISTALLSJUKAN (The Crystal Disease).

I also love explaining to patients how it works, because I think the body is a pretty clever contraption.

Vertigo is the illusion of movement, a spinning or rotatory form of dizziness. It usually originates in the balance organ, called the labyrinth, in the inner ear. Two common causes of vertigo are labyrinthitis, which is a viral infection, and Benign Positional Vertigo, which I wish we also would call the Crystal Disease.

This is how it works:

The labyrinth has two parts, the otololith organ and the semicircular canals. They are connected and filled with a sort of hydraulic fluid that we call the endolymph. Each inner ear, left and right, has this setup, and normally they provide the brain with the same, consistent information on where in space we are – but not always.

The otolith organ has one chamber, the utricle, that registers movement along a flat surface, like me rolling around the exam room on my stool (that’s how I demonstrate this). I hold my hands up with fingers pointing to the ceiling. “There are nerve cells in the otolith organ with little hairs sticking up like this”, I explain. Touching each fingertip with my other hand, I continue “and there is a weight, a little crystal, attached to the top of each of these hairs. If I move like this (stool roll..) the crystals make the little hairs bend, actually exaggerating the movement so I can register the slightest change in my position along this level path…”

The other chamber in the otolith organ, called the saccule, is set up to register movement in a vertical plane. Here I scrunch down or straighten up as I sit on my stool.

The Semicircular canals are curved tubes running in three different planes. They have a wider portion at one end with hairy nerve cells, similar to the otolith organ but without the crystals. When we turn our heads, the endolymph (fluid) movement causes the little hairs in each of the three semicircular canals to move a little differently and bend the nerve cell hairs to a different degree and maybe even in a different direction. All this information gives the brain a detailed sense of where in space we are.

Sometimes the little crystals fall off the hairs they’re sitting on top of in the otolith organ and travel with the endolymph into the semicircular canals.

Imagine what happens if the balance organ on one side tells the brain “movement to the left, thirty degrees” (here, I make the fingers on my left hand wiggle in unison just a little) and the other side, because some crystals flattened the nerve cell hairs, reports “wow, we’re upside down” (right hand and arm making a slam dunk movement). For at least a brief moment, our poor brains believe the louder, more dramatic yet inaccurate alarm report and we feel quite ill from that.

This explains why, in Benign Positional Vertigo, head movements in one direction can be much worse than movements in a different direction, depending on which angle causes the most dramatic effect from the little crystals.

This situation can go away spontaneously as the crystals can end up randomly traveling away from where the nerve cells register them.

There are also head maneuvers that can force the crystals away from the semicircular canals. Physical therapists and doctors in the specialties that deal the most with dizziness can put people through these movements, and you can even find instructions online.

Here is one of the most comprehensive explanations of all this that I have come across:

Lastly, a clinical pearl from Harvard’s neurology professor Dr. Martin Samuels 1945-2023). In his classic lecture on dizziness, he warns us never to suggest specific aspects of this symptom when taking a history. Most patients with dizziness will say yes to any description you suggest to them, therefore making diagnosis nearly impossible. Instead, he calls on his physician audience to repeat the word “dizzy”, maybe even a few times, scratch their chin and fix their gaze on something outside the window while rubbing their chin now and them – for however long it takes – until the patient starts to describe their symptoms themselves. Once they do, the diagnosis usually presents itself very plainly.