Hearing Loss in One Ear: Causes, Concerns, and What to Do

Hearing loss that affects only one ear — known as unilateral hearing loss or single-sided deafness (SSD) — can be particularly disorienting. It affects your ability to localise sounds, understand speech in noisy environments, and can feel isolating. Understanding the causes and knowing when to act is important.

Common causes

Hearing loss in one ear can have many causes, including:

• Ear wax blockage — the most common and easily treatable cause
• Ear infection (otitis media or otitis externa) — infection in the middle or outer ear
• Sudden sensorineural hearing loss (SSHL) — a medical emergency requiring prompt treatment
• Ménière's disease — a condition affecting the inner ear, causing hearing loss, vertigo, and tinnitus
• Acoustic neuroma (vestibular schwannoma) — a benign tumour on the hearing nerve
• Noise-induced hearing loss — asymmetric noise exposure (e.g., occupational)
• Eustachian tube dysfunction — poor ventilation of the middle ear

When to seek help

You should see a doctor as soon as possible if you experience:

• Sudden hearing loss in one ear — this is a medical emergency. Contact your GP immediately or go to A&E. Treatment with steroids within 24–72 hours offers the best chance of recovery.
• Gradual hearing loss in one ear — while less urgent, unilateral hearing loss should always be investigated to rule out underlying conditions such as acoustic neuroma.
• Hearing loss with other symptoms — dizziness, facial weakness, severe tinnitus, or discharge from the ear all warrant prompt medical attention.

Treatment options

Treatment depends on the cause. Wax removal and infection treatment can restore hearing completely. For permanent unilateral hearing loss, options include CROS hearing aids (which route sound from the deaf ear to the hearing ear), bone-anchored hearing aids (BAHAs), and cochlear implants in severe cases. Your audiologist or ENT specialist will advise on the most suitable option.