Adverse health consequences of undiagnosed hearing loss at middle age: A prospective cohort study with the UK Biobank

•This matched cohort study included 14,620 individuals with audiometry-determined objective hearing loss and 38,479 with subjective hearing loss, together with 29,240 and 38,479 matched unexposed individuals, respectively.•We found both undiagnosed objective and subjective hearing loss were associated with multiple subsequent adverse health consequences, but with discrepancies in comorbidity patterns.•Objective hearing loss had pronounced associations with neurodegenerative disease.•These findings highlight the importance of screening for speech-in-noise hearing impairment in the middle-aged population, for potential early diagnosis and intervention.