Vertigo happens when your brain receives conflicting signals about where your body is in space. The most common reason is a problem in the inner ear, though it can also stem from nerve inflammation, migraines, or certain medications. About one in three adults will experience vertigo at some point, with peak prevalence between ages 45 and 64.
How Your Balance System Works
Your brain constantly triangulates your position using three sources of information: sensory organs in your inner ear, your eyes, and pressure receptors in your muscles and joints. When all three agree, you feel stable. When one source sends a signal that conflicts with the others, the result is vertigo, that unmistakable false sensation of spinning or tilting.
The inner ear does most of the heavy lifting. It contains fluid-filled canals and tiny sensory organs that detect head rotation and the pull of gravity. These structures feed data to your brain, which triggers two automatic reflexes. One keeps your eyes locked on a target even when your head is moving. The other shifts your body weight to keep you upright. When something disrupts the inner ear or the nerve connecting it to the brain, both reflexes malfunction, and the world starts to spin.
Displaced Crystals: The Most Common Cause
The single most frequent cause of vertigo is a condition called BPPV (benign paroxysmal positional vertigo). Inside your inner ear, tiny calcium crystals sit on a sensory organ called the utricle, where they help you sense gravity. Sometimes these crystals break loose and drift into the semicircular canals, the fluid-filled tubes that detect head rotation.
Once there, the crystals shift every time you change head position: looking up, rolling over in bed, bending down. As they move, they push the fluid in the canal, which tricks the balance nerve into telling your brain your head is spinning when it isn’t. The posterior canal is the most commonly affected because it sits at the lowest point of the inner ear, making it a natural catch basin for stray crystals.
BPPV episodes are intense but brief. If you time them precisely, the spinning typically lasts 20 to 40 seconds, rarely more than a minute. They’re strongly tied to specific head movements, which is the key clue that crystals are the problem. A simple repositioning maneuver called the Epley, where your head is moved through a specific sequence of positions to guide the crystals out of the canal, is the standard treatment and works well for most people.
Fluid Buildup in the Inner Ear
Ménière’s disease causes vertigo through a different mechanism. The inner ear contains a fluid called endolymph, and in Ménière’s disease, too much of it accumulates. This excess fluid distorts the signals your inner ear sends to the brain, disrupting both balance and hearing.
Episodes feel different from BPPV. They typically last 30 minutes to a couple of hours, are often severe and incapacitating, and come with fluctuating hearing loss, ringing in the ear, or a feeling of fullness on one side. The timing is unpredictable. What triggers the fluid buildup isn’t fully understood, though allergies, prior head injuries, infections, and migraines are all associated with it.
Nerve and Inner Ear Inflammation
Two related inflammatory conditions cause vertigo, and the distinction between them matters. Vestibular neuritis is inflammation of the nerve that carries balance signals from the inner ear to the brain. Labyrinthitis is inflammation of the inner ear structures themselves. Both are most commonly triggered by viral infections.
The practical difference comes down to hearing. With vestibular neuritis, your hearing stays normal because the inflammation only affects the balance nerve. With labyrinthitis, the inflammation reaches the structures responsible for hearing, so vertigo comes alongside hearing loss or ringing in the ear. That hearing loss can be severe and is often permanent.
Unlike BPPV’s brief bursts of spinning, these inflammatory conditions cause continuous vertigo that persists for days or even weeks. The most intense phase usually occurs in the first few days, then gradually improves as the brain learns to compensate for the damaged signals.
Migraines and Vertigo
About one in three people who get migraines also experience vertigo, and the two don’t always happen together. Vestibular migraine can produce spinning, motion sensitivity, and disorientation that lasts anywhere from five minutes to three days. Some people get the vertigo during a headache. Others get it on its own, with no head pain at all.
What makes vestibular migraine tricky to identify is its range of triggers. The vertigo can come on spontaneously, after a change in head position, during head movement, or even in response to a visually busy environment like a crowded store or a fast-moving screen. At least half of episodes are accompanied by classic migraine features: sensitivity to light and sound, visual disturbances, or a pulsing one-sided headache. But the other half may not be, which is why this diagnosis is often missed or delayed.
Medications That Trigger Vertigo
A surprisingly long list of common medications can cause vertigo as a side effect. The mechanism varies. Some drugs are directly toxic to the inner ear structures. Others affect blood pressure or fluid balance in ways that disrupt the signals your brain relies on for orientation.
Categories that frequently cause vertigo include:
- Blood pressure and heart medications, particularly those that lower blood pressure quickly
- Certain antibiotics, especially a class called aminoglycosides, which can damage inner ear cells
- Anti-seizure drugs
- Anti-inflammatory drugs, including some common over-the-counter pain relievers and steroids
- Acid reflux medications like omeprazole and lansoprazole
- Opioid painkillers like codeine
- Sedatives and psychiatric medications, including benzodiazepines and lithium
If vertigo started or worsened around the time you began a new medication, that timing is worth noting. The vertigo often resolves when the medication is adjusted.
How Episode Duration Points to the Cause
One of the most useful things you can track is how long your vertigo lasts per episode, because different causes produce strikingly different patterns. Seconds to under a minute, triggered by rolling over or looking up, points strongly toward displaced crystals (BPPV). Episodes lasting 30 minutes to a few hours, especially with hearing changes on one side, suggest Ménière’s disease. Vertigo lasting minutes to days, with or without headache but with light or sound sensitivity, fits a vestibular migraine pattern. Continuous vertigo persisting for days that came on suddenly points to nerve inflammation like vestibular neuritis.
Doctors also look at whether something specific triggers the episodes. BPPV is almost always provoked by head position changes. Vestibular migraine can be triggered by visual stimulation, stress, or sleep changes. Ménière’s episodes often strike without a clear trigger, though salt intake and stress are sometimes involved.
When Vertigo Signals Something Serious
Most vertigo comes from the inner ear and, while miserable, isn’t dangerous. The concern is when vertigo originates in the brain, particularly from a stroke affecting the brainstem or cerebellum. This is called central vertigo, and it behaves differently from inner ear problems in ways that emergency physicians are trained to detect.
Red flags that suggest a brain-related cause include vertigo accompanied by difficulty walking or severe unsteadiness, double vision, slurred speech, weakness or numbness on one side of the body, or a new severe headache. Another clue is in the eyes: with inner ear vertigo, involuntary eye movements typically beat in one consistent direction. With brain-related vertigo, the eye movements may change direction when you look to different sides.
Current clinical guidelines recommend that emergency physicians use a bedside eye exam rather than a CT scan to distinguish brain-related vertigo from inner ear vertigo. CT scans miss most strokes that cause vertigo, while a structured eye movement test called HINTS, performed by a trained clinician, is highly accurate. MRI is reserved for cases where the eye exam is inconclusive or points toward a brain cause.