Merck Manual

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Some Causes and Features of Dizziness

Some Causes and Features of Dizziness

Cause

Common Features*

Diagnosis†

Common causes

Severe, brief (lasting less than 1 minute) spinning episodes triggered by moving the head in a specific direction, especially while lying down

Sometimes nausea and vomiting

Normal hearing and neurologic function

A doctor's examination, typically including the Dix-Hallpike maneuver

Multiple separate episodes of vertigo, each lasting 20 minutes to 2 hours, accompanied by ringing, hearing loss, and ear fullness/pressure usually in 1 ear only

Audiometry

Gadolinium-enhanced MRI

Vestibular neuronitis (probably caused by a virus)

Sudden, severe vertigo with no hearing loss or other findings

Severe vertigo may last several days, with gradual lessening of symptoms and possible development of positional vertigo

A doctor's examination

Sometimes gadolinium-enhanced MRI

Labyrinthitis (viral or bacterial cause)

Sudden hearing loss with severe dizziness, often with tinnitus

A doctor's examination

Audiometry

Temporal bone CT scan if doctors suspect a bacterial infection

Gadolinium-enhanced MRI for people with hearing loss and ringing in ear to exclude a tumor

Drugs that affect the inner ear (particularly aminoglycoside antibiotics, chloroquine, furosemide, and quinine)

Usually hearing loss in both ears

Possible causative drug recently started

A doctor's examination

Audiometry

Measuring blood levels of certain causative drugs

Sometimes electronystagmography and rotary chair tests to look for abnormal eye movements suggesting inner ear injury

Drugs that affect the brain overall (particularly drugs for anxiety, depression, and seizures, as well as sedative drugs in general)

Symptoms unrelated to movement or position

No hearing loss or other symptoms

Possible causative drug recently started

Measuring blood levels of certain causative drugs

Stopping the drug to see whether symptoms stop

Multiple, separate episodes of vertigo, or chronic dizziness, sometimes accompanied by nausea

Headache or other migraine symptoms such as visual or other aura (altered sensations that come before the headache such as flashing lights) and sensitivity to light and/or noise

Often history or family history of migraine

A doctor's examination

Sometimes MRI to rule out other causes

Trial of drugs to treat and prevent migraine

Less common causes, typically with ear symptoms (hearing loss and/or ringing in the ear)

Middle ear infection (acute or chronic)

Ear pain, sometimes discharge from the ear

Abnormal appearance of the eardrum during examination

A doctor's examination

Audiometry

Sometimes CT scan (for people with chronic infection)

Trauma (such as ruptured eardrum, skull fracture, or concussion)

Obvious recent trauma

Other findings depending on location and extent of damage

A doctor's examination

Audiometry

Sometimes CT

Slowly progressive hearing loss and ringing in one ear

Rarely, numbness and/or weakness of the face

Audiometry

Gadolinium-enhanced MRI if hearing loss or tinnitus

Defect of the bone around a semicircular canal

Dizziness triggered by sound, low tone hearing loss

Audiometry with tympanometry

Usually a CT scan

Usually vestibular testing

Less common causes, typically without ear symptoms

Brain stem stroke

Sudden onset, continuous symptoms

Immediate gadolinium-enhanced MRI

Bleeding in the cerebellum

Sudden onset, with continuous symptoms

Difficulty walking and with tests of coordination

Often headache

Symptoms worsen rapidly

Immediate gadolinium-enhanced MRI

Multiple, separate episodes of neurologic symptoms such as weakness or numbness with different episodes affecting different parts of the body

Gadolinium-enhanced MRI of brain and spine

Low blood sugar (usually caused by drugs for diabetes)

Recent dose increase

Sometimes sweating

Finger-stick glucose test (during symptoms if possible)

Low blood pressure (such as caused by heart disorders, blood pressure drugs, blood loss, or dehydration)

Symptoms when rising, but not with head motion or while lying flat

Symptoms of the cause often obvious (such as severe blood loss or diarrhea)

Testing directed at suspected cause

Pregnancy (often not known by the person)

Sometimes late menstrual period and/or morning sickness

No ear symptoms

Pregnancy test

Chronic symptoms with on and off hearing loss in both ears and episodes of vertigo

Audiometry

Syphilis blood test

Weight change

Heat or cold intolerance

Thyroid function blood tests

* Features include symptoms and results of the doctor's examination. Features mentioned are typical but not always present.

† Although a doctor's examination is always done, it is only mentioned in this column if the diagnosis can sometimes be made only by the doctor's examination, without any testing. In other words, additional tests may not be needed.

CT = computed tomography; MRI = magnetic resonance imaging.