Labyrinthitis

What it means

Deep inside the ear, beyond the eardrum, sits a delicate, fluid-filled structure called the labyrinth, which houses both the balance organs and the hearing organ (the cochlea). This condition is inflammation of that whole structure, most often triggered by a viral infection, which disrupts the normal balance and hearing signals it sends to the brain. It differs from a related, more limited condition that affects only the balance nerve and spares hearing.

Because inflammation affects both the hearing and balance portions of this inner-ear structure together, it typically causes sudden vertigo along with hearing loss or ringing, distinguishing it from other causes of dizziness that leave hearing untouched.

Why it appears on a CT or MRI report

This is primarily a clinical diagnosis, made from the history and a physical exam, but MRI of the brain and inner ears is often ordered to rule out other, more serious causes of sudden vertigo and hearing loss, such as a stroke or a tumor. On a contrast-enhanced MRI, the inflamed inner ear structure may show abnormal enhancement, meaning it lights up more than expected after contrast dye is given, which supports the diagnosis. CT is less useful for seeing the inflammation itself but can help rule out other bony or structural ear problems.

What it usually means

Most cases follow a viral illness, such as a cold or flu, or sometimes an ear infection that has spread inward; less commonly, it can accompany conditions like shingles affecting the ear. It typically causes sudden, severe vertigo (a spinning sensation), nausea and vomiting, unsteadiness, and hearing loss or ringing in the affected ear, often lasting days before gradually improving as the brain adapts and the inflammation settles. While uncomfortable and sometimes frightening, most people recover well, though some are left with lingering imbalance or, less often, some permanent hearing loss on the affected side. Because its symptoms can overlap with a stroke affecting the same part of the brainstem or cerebellum, doctors take sudden vertigo seriously until other causes are excluded.

When to follow up

If you are diagnosed with this condition, your doctor may prescribe medication to ease nausea and dizziness, sometimes a short course of steroids, and possibly balance-focused physical therapy (vestibular rehabilitation) if symptoms linger. Follow up with an ear, nose, and throat specialist or audiologist if hearing loss persists after the acute episode settles, since early treatment can sometimes help recovery. Seek emergency care for sudden vertigo accompanied by double vision, slurred speech, weakness, numbness, or trouble walking straight, since these combinations can signal a stroke rather than this inner-ear condition and need urgent evaluation.

A plain-language way to picture it

Think of the inner ear's balance and hearing organ as a finely tuned instrument sending a constant, steady signal to the brain about which way is up and what sounds are present. Inflammation is like static interference suddenly flooding that signal — the brain receives garbled, conflicting information, which is exactly why the room seems to spin and sounds may become muffled or ring. As the inflammation settles and the static clears, the signal steadies again, and for most people, balance and hearing return close to normal.