Short answer
Hypofunction means one or both inner ears send weaker balance signals. With unilateral hypofunction, the mismatch between the two sides causes dizziness, blurry vision with quick head turns and drifting. With bilateral hypofunction, both sides are weak, so people feel unsteady in the dark or on uneven ground and see the world bounce when they walk. Vestibular rehabilitation is strongly recommended for both1.
Answered by Dr. Manan Patel, PT, DPT, TPS, Certified Vestibular Specialist and Therapeutic Pain Specialist. Updated October 18, 2026.
What causes vestibular hypofunction?
One-sided loss often follows vestibular neuritis or labyrinthitis, Ménière's disease or treatment of a vestibular schwannoma. Two-sided loss can follow certain antibiotics (especially aminoglycosides such as gentamicin), Ménière's disease in both ears, meningitis or autoimmune disease, and in many people no cause is found2.
Why is walking in the dark or on grass so hard with bilateral hypofunction?
Balance relies on three inputs: the inner ears, vision and sensation from the feet and joints. When both inner ears are weak, the brain leans on vision and the feet. Take away light or a firm, flat surface and little is left to balance with. Oscillopsia, the bouncing of the visual world when walking, happens because the vestibulo-ocular reflex can no longer hold the eyes steady2.
How do you measure vestibular hypofunction in the clinic?
We test the vestibulo-ocular reflex with head impulse and dynamic visual acuity testing, look for spontaneous and head-shaking nystagmus under infrared video goggles, and use BioSway computerized balance testing, including the four modified CTSIB conditions (eyes open and closed, on firm and foam surfaces), to see which inputs you rely on3. When formal caloric or rotary chair testing is needed, we coordinate with your ENT or audiologist.
What does treatment look like in Cumming and Alpharetta?
For one-sided loss, gaze stabilization and habituation drive central compensation, so symptoms settle even when the ear itself does not recover. For two-sided loss, the focus shifts to substitution: training vision, foot sensation and safer movement strategies, plus home changes such as night lights. At our Cumming clinic, patients with significant instability can practice walking challenges in the Zero-Fall overhead harness. Most programs last several weeks, with repeat testing to track gains.
Where can I get help in Alpharetta, Cumming and nearby?
Dr. Manan Patel, PT, DPT, TPS and our team of physical therapists see patients from Alpharetta, Johns Creek, Milton, Roswell, Cumming, Suwanee, Sugar Hill, Buford, Duluth and Forsyth County at two North Atlanta clinics. Every visit is 60 minutes, one-on-one, and urgent appointments are available within 48 hours. We are in-network with Traditional Medicare, BCBS / Anthem and Tricare, and offer a $129 rate per visit for self-pay and out-of-network plans. Not sure where to start? Take the free symptom self-check, or visit our Alpharetta clinic or Cumming clinic page.
Cumming clinic
Off GA-400 Exit 13 on Peachtree Parkway
Cumming, GA 30041
Alpharetta clinic
Inside Georgia Brain & Spine Physical Therapy
Alpharetta, GA 30022
Related care
Related questions
- Vestibular neuritis vs. labyrinthitis: how long does recovery take after a viral inner ear infection?Both start with sudden, severe vertigo that lasts days. Vestibular neuritis inflames the balance nerve and spares…2 min read · Patient question
- Living with Ménière's disease: can vestibular therapy help your balance between vertigo attacks?Yes, for the imbalance between attacks. Ménière's disease causes episodes of vertigo lasting 20 minutes to 12 hours,…2 min read · Patient question
- Can vestibular rehab help after acoustic neuroma treatment or with vestibular paroxysmia?After surgery or radiation for an acoustic neuroma (vestibular schwannoma), the balance nerve on that side is often…2 min read · Patient question
- All vestibular rehabilitation and vertigo questionsBrowse every question in this topic.
References
- Hall CD, et al. Vestibular Rehabilitation for Peripheral Vestibular Hypofunction: An Updated Clinical Practice Guideline. Journal of Neurologic Physical Therapy. 2022.
- Strupp M, et al. Bilateral vestibulopathy: Diagnostic criteria. Journal of Vestibular Research. 2017.
- Shumway-Cook A, Horak FB. Assessing the influence of sensory interaction on balance: suggestion from the field. Physical Therapy. 1986.
This answer is general education, not a diagnosis or a substitute for an examination. If you have new or worsening symptoms, contact your doctor. Call 911 for sudden severe dizziness with trouble speaking, weakness, numbness, double vision or a severe headache.
