Vertigo is caused by a problem in how your body detects motion and balance, almost always originating in the inner ear or, less commonly, in the brain. The single most common cause is tiny calcium crystals dislodging inside the inner ear, a condition called benign paroxysmal positional vertigo (BPPV). But several other conditions, medications, and neurological problems can trigger vertigo too, and knowing the difference matters because some causes resolve on their own while others need immediate attention.
How Your Balance System Works
Understanding what causes vertigo starts with understanding how your body tracks movement in the first place. Deep inside each ear sits a set of fluid-filled structures called the vestibular system. This system has two main parts: three semicircular canals that detect rotation (turning your head left, right, up, or down) and two otolith organs that detect linear movement and gravity (like riding in an elevator or tilting your head).
All of these structures are filled with a fluid called endolymph. When your head moves, the fluid shifts and pushes against microscopic hair cells embedded in a gel-like membrane. Those hair cells convert the movement into nerve signals that travel to your brain, telling it exactly where your head is in space. Your brain combines that information with what your eyes see and what your muscles and joints feel to keep you balanced. When any part of this chain sends a faulty signal, or when one ear sends a different signal than the other, the mismatch registers as vertigo.
BPPV: The Most Common Cause
Benign paroxysmal positional vertigo accounts for more cases of vertigo than any other single condition. It happens when tiny calcium carbonate crystals called otoconia, which normally sit on a sticky membrane inside the otolith organs, break free and drift into one of the semicircular canals. Once there, the loose crystals settle at the lowest point of the canal whenever you change head position. That displacement pushes fluid around, stimulating the hair cells and sending a false rotation signal to your brain.
The hallmark of BPPV is brief, intense spinning triggered by specific movements: looking up, rolling over in bed, bending forward, or going from lying down to sitting. Episodes typically last less than a minute but can be severe enough to cause nausea. BPPV is not dangerous, and in many cases it can be resolved in one or two office visits through a series of guided head movements (called repositioning maneuvers) that guide the loose crystals back to where they belong.
Ménière’s Disease and Fluid Buildup
Ménière’s disease results from an abnormal buildup of endolymph, the same fluid that normally helps detect motion. When the drainage pathway for this fluid becomes obstructed, pressure increases inside the inner ear’s delicate membranes. That excess pressure distorts the structures responsible for both hearing and balance, producing a distinctive set of four symptoms: episodes of spinning vertigo (sometimes violent), fluctuating hearing loss, a low-pitched ringing or roaring in the ear, and a feeling of fullness or pressure in the affected ear.
Unlike BPPV, Ménière’s episodes can last anywhere from 20 minutes to several hours. They tend to come and go unpredictably, with symptom-free stretches between attacks. Over time, hearing loss may become permanent in the affected ear. The exact reason the fluid drainage fails is still not fully understood, which makes Ménière’s harder to treat than BPPV. Management focuses on reducing the frequency and severity of episodes, often through dietary salt restriction and medications that help control fluid retention.
Vestibular Neuritis and Labyrinthitis
Both of these conditions involve inflammation in or around the inner ear, usually triggered by a viral infection like a cold or flu. The difference between them is straightforward: vestibular neuritis inflames the nerve that carries balance signals from the inner ear to the brain, while labyrinthitis inflames the inner ear structure itself. Because the inner ear handles both balance and hearing, labyrinthitis causes vertigo along with hearing loss or ringing. Vestibular neuritis causes vertigo alone, with hearing unaffected.
These infections tend to come on suddenly and can produce severe, constant vertigo lasting days, gradually fading over one to three weeks. Because the cause is almost always viral, antibiotics don’t help. Recovery involves letting the inflammation resolve while managing symptoms. Most people recover fully, though some experience lingering balance issues for weeks or months as the brain recalibrates to the temporarily weakened signal from one ear.
Central Causes: When the Problem Is in the Brain
A small but important fraction of vertigo cases originate not in the ear but in the brain, specifically in the brainstem or cerebellum, the regions that process balance signals. Strokes, particularly in the arteries feeding the back of the brain, can damage these areas and produce vertigo that feels similar to an inner ear problem. In one large study of over 900 patients presenting with dizziness, about 5% had a serious neurological diagnosis, most commonly a stroke or other cerebrovascular event.
Other central causes include tumors (such as acoustic neuromas growing on the balance nerve), multiple sclerosis, traumatic brain injury, and infections that reach the brain. These conditions are far less common than inner ear problems, but they’re more dangerous. Cerebellar strokes, for instance, carry mortality rates between 7% and 17% depending on which artery is affected.
Warning Signs of a Dangerous Cause
Certain features help distinguish brain-related vertigo from the more common inner ear variety. Vertigo that comes with any of the following warrants emergency evaluation: difficulty walking or severe imbalance out of proportion to the dizziness, new double vision, slurred speech, weakness or numbness on one side of the body, or severe headache. The character of involuntary eye movements (called nystagmus) also differs. In inner ear vertigo, the eyes typically drift in one consistent direction. In brain-related vertigo, the eye movements may change direction depending on where the person looks, or move vertically, both of which point to a central problem.
Medications That Damage the Inner Ear
Certain drugs are directly toxic to the inner ear’s hair cells, a side effect called ototoxicity. When these cells are damaged, balance signals become unreliable, leading to dizziness, unsteadiness, and sometimes true vertigo. The most commonly implicated drug classes include certain intravenous antibiotics (particularly the aminoglycoside family), platinum-based chemotherapy drugs, and loop diuretics used to treat fluid retention. Even high doses of aspirin can temporarily affect inner ear function.
Ototoxic damage can be temporary or permanent depending on the drug, the dose, and how long it’s used. Balance problems from these medications often show up as unsteadiness while walking or climbing stairs rather than the dramatic spinning of BPPV. If you’re on a medication known to affect the inner ear and you notice new balance problems or hearing changes, that’s worth raising with whoever prescribed it.
Other Ear-Related Causes
Chronic ear infections can occasionally cause vertigo when infection erodes through the bone separating the middle ear from the inner ear, allowing bacteria to reach the balance organs and trigger labyrinthitis. A cholesteatoma, an abnormal skin growth in the middle ear, can do the same thing by gradually eroding surrounding bone. Both of these are treatable but require medical or surgical intervention to prevent further damage.
Head injuries are another common trigger. A blow to the head can dislodge otoconia (causing BPPV), damage the vestibular nerve, or cause small bleeds in the brainstem’s balance centers. Post-traumatic vertigo sometimes resolves within weeks, but it can also persist for months depending on the severity and location of the injury.
Why Identifying the Cause Matters
The causes of vertigo range from a 30-second repositioning fix to a medical emergency, and the spinning sensation itself feels remarkably similar across all of them. What separates them is the pattern. BPPV lasts seconds and is triggered by position changes. Vestibular neuritis comes on suddenly and lasts days. Ménière’s disease produces episodes lasting minutes to hours with hearing symptoms. Central vertigo often comes with neurological signs like vision changes or coordination problems.
Paying attention to how long episodes last, what triggers them, whether hearing is affected, and whether any other neurological symptoms are present gives your doctor the most important clues for pinpointing the cause and getting you the right treatment.