Which investigations should be performed in primary care to rule out underlying causes of sudden sensorineural hearing loss?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 22 August 2025Updated: 22 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX
In primary care, the initial investigations for sudden sensorineural hearing loss primarily involve ruling out common external and middle ear causes and then prompt referral to specialist services .
  • Exclude impacted earwax and acute infections such as otitis externa .
  • If earwax is contributing to the hearing loss, it should be removed in primary care using methods like an electronic irrigator, microsuction, or manual removal .
  • For adults with sudden onset or rapid worsening of hearing loss (developed over 3 days or less) that is not explained by external or middle ear causes, the following referrals are crucial:
    • If the hearing loss developed within the past 30 days, refer immediately (to be seen within 24 hours) to an ear, nose and throat (ENT) service or an emergency department .
    • If the hearing loss developed more than 30 days ago, refer urgently (to be seen within 2 weeks) to an ENT or audiovestibular medicine service .
  • Refer immediately (to be seen within 24 hours) adults with acquired unilateral hearing loss and altered sensation or facial droop on the same side to an ENT service, or follow a local stroke referral pathway if stroke is suspected .
  • Consider referring adults to an ENT service if, after initial treatment of any earwax or acute infection, they have persistent issues such as pain affecting either ear for 1 week or more, unresolved or recurrent discharge, or an abnormal appearance of the outer ear or eardrum .

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