Vertigo can be triggered by dozens of different things, from tiny calcium crystals shifting inside your ear to something as simple as not drinking enough water. The most common trigger by far is a sudden change in head position that displaces debris in your inner ear, but infections, migraines, medications, and even stress can set off episodes. Nearly 40% of adults over 55 develop some form of vertigo or dizziness over a 10-year period, making it one of the most widespread sensory complaints.
Loose Crystals in Your Inner Ear (BPPV)
The single most common cause of vertigo is benign paroxysmal positional vertigo, or BPPV. Inside your inner ear, tiny calcium carbonate crystals (ranging from 1 to 30 micrometers) sit on a gel-like membrane in a structure called the utricle, where they help you sense gravity. Sometimes chunks of this membrane, crystals and all, break free and drift into the semicircular canals, the fluid-filled loops your brain uses to detect rotation.
Once that debris is floating where it shouldn’t be, any head movement that shifts it creates an abnormal current in the fluid. Your brain interprets that current as spinning, even though you’re barely moving. Rolling over in bed, tilting your head back to look up, or bending forward can all set it off. Episodes are usually intense but brief, lasting seconds to a minute. BPPV becomes more common with age, after head injuries, and after prolonged bed rest.
Fluid Buildup and Ménière’s Disease
Ménière’s disease produces vertigo episodes that last much longer, typically hours at a time, and come with hearing loss, ringing in the ear, and a feeling of fullness. The underlying problem is an excess buildup of fluid (endolymph) in the inner ear, which distorts the delicate membranes that detect sound and motion.
What triggers individual attacks often comes down to diet and lifestyle. High salt intake changes the concentration of electrolytes in your blood, which in turn alters the composition of inner ear fluid and can provoke an episode. Caffeine and alcohol constrict blood vessels, potentially reducing blood flow to the inner ear and worsening symptoms. Many people with Ménière’s find they can reduce the frequency of attacks by cutting back on salt, caffeine, and alcohol, though the evidence base for these dietary changes is still limited.
Vestibular Migraines
If you get migraines and also experience vertigo episodes that last anywhere from five minutes to 72 hours, vestibular migraine is a likely culprit. This is one of the most underdiagnosed vertigo triggers because the spinning doesn’t always come with a headache. You might have the vertigo on its own, or the dizziness and headache might happen at different times during the same episode.
The triggers overlap heavily with those for regular migraines: stress, sleep deprivation, certain foods, hormonal changes, bright or flickering lights, and weather shifts. Interestingly, motion itself can trigger an attack. Vestibular stimulation, like a boat ride or a car on winding roads, can kick off a full migraine episode in susceptible people. A formal diagnosis requires at least five episodes with moderate to severe vestibular symptoms in someone with a current or past history of migraine.
Viral Infections and Inner Ear Inflammation
A sudden, severe vertigo episode that lasts days and comes on after a cold or upper respiratory infection points toward vestibular neuritis or labyrinthitis. Both involve inflammation of the nerves or structures in the inner ear, usually triggered by a viral infection. Herpes viruses (including the one that causes shingles) are among the suspected culprits, and in rare cases Lyme disease or other infections can be responsible.
Vestibular neuritis affects the balance nerve alone, so you get vertigo without hearing loss. Labyrinthitis inflames a broader area and typically causes both vertigo and sudden hearing changes. The worst of the spinning usually resolves within a few days, but a vague sense of imbalance can linger for weeks or months as the brain recalibrates.
Medications That Cause Vertigo
The list of drugs that can trigger vertigo or dizziness is surprisingly long. The most frequently reported offenders fall into a few major categories:
- Anti-seizure medications: drugs that stabilize overactive nerve cells are among the most common pharmaceutical triggers
- Blood pressure medications: calcium channel blockers and certain combinations of other blood pressure drugs can provoke episodes
- Antidepressants: several common antidepressants, particularly SSRIs, can cause vertigo and dizziness alongside fatigue
- Antibiotics: certain fluoroquinolone antibiotics and some penicillin-type drugs list dizziness as a side effect
- Sedatives and tranquilizers: anything that depresses the central nervous system can interfere with balance processing
If vertigo starts shortly after beginning a new medication or changing a dose, the drug is a strong suspect. Don’t stop taking prescribed medications on your own, but it’s worth flagging the timing with whoever prescribed them.
Dehydration and Stress
Not drinking enough water can directly affect your inner ear. When you’re dehydrated, your body ramps up production of a hormone called vasopressin to conserve water. Higher vasopressin levels alter how water moves through the inner ear’s membranes, potentially contributing to the same kind of fluid imbalance seen in Ménière’s disease. Vasopressin’s central effects on the brain may also trigger nausea and motion sensitivity.
Chronic stress works through a similar pathway. Repeated psychological pressure increases vasopressin receptor activity even when you’re drinking enough water, essentially mimicking the hormonal state of dehydration. This helps explain why stressful periods so often coincide with vertigo flare-ups, especially in people already prone to vestibular problems. Staying well-hydrated and managing stress won’t cure an underlying vestibular condition, but both can meaningfully reduce how often episodes strike.
Benign Tumors on the Balance Nerve
A vestibular schwannoma (also called acoustic neuroma) is a slow-growing, noncancerous tumor that forms on the sheath of the balance nerve. It’s far less common than the triggers above, but worth knowing about because its symptoms creep up gradually over months to years. The hallmark is one-sided hearing loss, but somewhere between 40% and 75% of people with these tumors also develop vestibular symptoms, usually a vague sense of imbalance rather than dramatic spinning.
Because the brain has time to compensate as the tumor grows slowly, the vertigo from a schwannoma tends to be milder than what you’d experience with BPPV or vestibular neuritis. Persistent one-sided hearing loss or tinnitus that worsens over time is the signal to get imaging.
When Vertigo Signals Something Serious
Most vertigo comes from the inner ear and, while miserable, isn’t dangerous. But vertigo can occasionally be the primary symptom of a stroke affecting the back of the brain, particularly the cerebellum. A cerebellar stroke can look almost identical to a routine inner ear problem because vertigo and imbalance may be the only obvious symptoms.
Several red flags distinguish a potentially dangerous episode from a benign one:
- Double vision, slurred speech, trouble swallowing, or hoarseness alongside vertigo strongly suggest a stroke
- Inability to sit upright without support (severe truncal ataxia) was the only visible neurological sign in nearly 30% of stroke patients initially thought to have simple vertigo
- Sudden, severe headache or neck pain during a vertigo episode can indicate a vertebral artery dissection or cerebellar infarction
- Recent head or neck trauma, even minor, raises the risk of arterial dissection and should be taken seriously if vertigo follows
One useful distinction: vertigo caused by reduced blood flow to the brain typically lasts minutes, while inner ear vertigo tends to last hours. A vertigo episode that comes with any new neurological symptom, no matter how subtle, warrants emergency evaluation.