Vertigo is triggered when your brain receives conflicting or faulty signals about your body’s position in space, and the cause is usually traceable to a specific problem in the inner ear. Roughly one in five adults experiences vertigo at least occasionally, with lifetime prevalence estimates ranging from 3% to 10% for recurrent episodes. The triggers vary widely, from something as simple as rolling over in bed to infections, migraines, and medications.
Loose Crystals in the Inner Ear
The single most common cause of vertigo is benign paroxysmal positional vertigo, or BPPV. Inside each inner ear, tiny calcium carbonate crystals help you sense gravity. These crystals can break free from their normal position and drift into one of the three semicircular canals, which are fluid-filled tubes designed to detect head rotation. Once loose crystals enter a canal, they slosh around with head movements and push on sensory hair cells that were never meant to be stimulated that way. Your brain interprets this as spinning, even though you’re barely moving.
BPPV episodes are brief. If you time them precisely, they typically last 20 to 40 seconds, though they feel much longer. They’re triggered by specific position changes: tilting your head back, rolling over in bed, bending forward, or looking up. The crystals often detach due to age-related wear on the inner ear structures, but head injuries, prolonged bed rest, and ear surgeries can also shake them loose.
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, the volume of this fluid increases abnormally, stretching the delicate membranes that contain it. This distension, called endolymphatic hydrops, disrupts the balance organs and the hearing structures at the same time. The membranes of the saccule (a gravity-sensing organ) are particularly vulnerable because they’re thinner and stretch more easily than those in the semicircular canals.
Ménière’s episodes are longer and more intense than BPPV, usually lasting 30 minutes to a couple of hours. They often come with fluctuating hearing loss (especially for low-pitched sounds), a feeling of fullness in the affected ear, and ringing or roaring tinnitus. Atmospheric pressure changes can act as a trigger. Research published in PLOS One found that a rise in barometric pressure increased the odds of a Ménière’s episode the following day by up to 24%. The pressure appears to alter fluid dynamics in the inner ear, worsening the existing fluid imbalance.
Migraines That Affect Balance
More than 60% of people who get migraines with brainstem aura report vertigo, but you don’t always need a headache for a migraine to affect your balance. Vestibular migraine causes moderate to severe vertigo episodes lasting anywhere from five minutes to 72 hours. At least half of these episodes come with typical migraine features: one-sided pulsing head pain, sensitivity to light and sound, or visual aura. Some people experience the vertigo without any headache at all, which makes it harder to recognize.
The same triggers that set off regular migraines can bring on vestibular migraine episodes: stress, sleep deprivation, hormonal shifts, certain foods, and bright or flickering lights.
Infections and Nerve Inflammation
Viral infections can inflame inner ear structures and cause vertigo that lasts days to weeks. The two main conditions here are vestibular neuritis and labyrinthitis, and the key difference between them is hearing. Vestibular neuritis affects only the nerve connecting the inner ear to the brain, producing prolonged vertigo without significant hearing loss. Labyrinthitis inflames the entire labyrinth (the combined balance and hearing organ), so it causes both vertigo and hearing loss.
Both conditions typically follow an upper respiratory infection or viral illness. The vertigo is constant rather than triggered by position changes, and it’s often severe enough to cause nausea and vomiting. Most people improve gradually over one to three weeks as the brain compensates for the damaged signals, though some residual imbalance can linger for months.
Medications That Cause Vertigo
A surprisingly long list of medications can trigger vertigo or dizziness as a side effect. The most common culprits fall into several categories:
- Anti-seizure drugs such as lamotrigine, oxcarbazepine, and carbamazepine, which account for roughly half of drug-related vertigo reports in pharmacovigilance data
- Blood pressure medications including calcium channel blockers and certain combinations of angiotensin receptor blockers with diuretics
- Antidepressants particularly SSRIs like paroxetine and sertraline, which often cause vertigo alongside fatigue
- Antibiotics including fluoroquinolones like ciprofloxacin and certain penicillin combinations
- Other drugs including proton pump inhibitors, anti-inflammatory painkillers, and antipsychotics
If vertigo starts shortly after beginning a new medication or changing a dose, that timing is an important clue. The vertigo often resolves when the drug is adjusted.
How Episode Length Points to the Cause
The duration of your vertigo episodes is one of the most useful clues for identifying the trigger. Seconds to under a minute, especially with head movements, points strongly toward BPPV. Episodes lasting 30 minutes to a few hours suggest Ménière’s disease, particularly if hearing changes accompany them. Vestibular migraine episodes can stretch from minutes to days. Constant vertigo lasting days or weeks usually indicates nerve inflammation from an infection.
There’s also a general pattern worth knowing: vertigo lasting seconds to minutes is more likely to originate in the inner ear itself. Vertigo lasting hours to days raises more concern about problems in the brainstem or brain.
When Vertigo Signals Something Serious
Most vertigo comes from the inner ear and, while miserable, isn’t dangerous. But vertigo can occasionally signal a stroke or other brain problem, and certain symptoms help distinguish the two.
Inner ear vertigo typically produces side-to-side eye movements (nystagmus) that calm down when you focus on a fixed object. You can usually still stand and walk with some assistance, even if you feel unsteady. Central vertigo, originating in the brain, tends to produce different eye movements that don’t settle with visual focus and may be purely vertical or rotational. People with central vertigo often can’t stand or walk at all, which sets them apart from those with inner ear problems.
Vertigo accompanied by weakness on one side of the body, vision loss, slurred speech, difficulty swallowing, or altered consciousness needs emergency evaluation. These combinations suggest a stroke affecting the brainstem or cerebellum, areas that process balance signals. The vertigo itself may feel identical to an inner ear episode, so these additional neurological symptoms are what matter most for spotting something urgent.