Obstructive sleep apnea (OSA) is usually described by its hallmark symptom: feeling exhausted and nodding off during the day despite a full night in bed. But a review published in Sleep Medicine Reviews finds that in adults 65 and older, that textbook symptom is often absent — and the disorder shows up instead as memory lapses, trouble concentrating, and slower thinking that can be mistaken for ordinary aging or the early stages of dementia.
A Different Presentation in Later Life
The review, titled "OSA in the aging population: Diagnostic and therapeutic considerations" and authored by Michael V. Vitiello of the University of Washington and David Gozal of the University of Missouri, examined how obstructive sleep apnea's clinical picture shifts with age. In younger and middle-aged adults, loud snoring, witnessed breathing pauses, and excessive daytime sleepiness are the symptoms that typically prompt a sleep study. The authors found that older adults with OSA frequently lack that last symptom entirely, even when their breathing is disrupted just as severely overnight.
Instead, the cognitive fallout tends to dominate. The review links OSA in older adults to measurable problems with attention, memory, and executive function — the mental skills involved in planning, organizing, and switching between tasks. Because those are also the domains that decline with normal aging and in early dementia, the authors warn that sleep apnea can easily hide in plain sight, dismissed by patients, families, and even clinicians as an unavoidable consequence of getting older.
Why the Symptom Gap Matters
The mismatch has practical consequences. Standard screening tools for sleep apnea, including patient-facing questionnaires, were largely developed and validated using symptom patterns seen in younger populations, with daytime sleepiness as a central scoring item. A patient over 65 who sleeps poorly, wakes up repeatedly through the night, but denies feeling sleepy during the day may score low on those tools and never get referred for a diagnostic sleep study — even if an overnight test would show frequent breathing interruptions and oxygen drops.
That gap between how OSA is screened for and how it actually presents in older adults compounds an existing underdiagnosis problem. Separate research cited in the surrounding literature has found that a large share of older adults who meet high-risk criteria based on their symptom profile have never been tested for the condition, and that self-reported screening measures can substantially understate how many older adults are actually living with moderate-to-severe apnea.
The Proposed Mechanism
The review ties the cognitive symptoms to the same physiological disruptions that drive OSA's cardiovascular effects: repeated drops in blood oxygen, fragmented sleep architecture that prevents adults from reaching restorative deep and REM sleep stages, and surges in blood pressure each time breathing resumes after a pause. Gozal and Vitiello argue these stresses don't stay confined to the heart and blood vessels — they also affect the brain, which is particularly vulnerable to oxygen fluctuations and vascular strain during the hours it would otherwise be consolidating memories and clearing metabolic waste.
The authors stop short of claiming OSA causes dementia outright. Their point is narrower and, for clinical practice, more immediately useful: in older patients, apnea-driven cognitive symptoms can look identical to the cognitive symptoms of aging or neurodegenerative disease, and ruling out treatable sleep apnea should come before assuming the latter.
What This Means for Patients
This is a review of existing evidence rather than a new clinical trial, and it does not establish that treating sleep apnea reverses cognitive decline once it has set in — other research suggests the picture there is mixed, with some older patients improving on CPAP therapy and others not. What the review does add is a clearer picture of why apnea goes unrecognized in this age group: clinicians and patients are often looking for the wrong symptom.
For adults over 65 who have noticed new memory slips, trouble concentrating, or a general mental fog — particularly if they also snore, wake frequently during the night, or have a bed partner who has observed pauses in breathing, even without feeling notably sleepy during the day — this review is a reason to ask a doctor about a sleep evaluation rather than assume the changes are simply part of aging. Sleep apnea is treatable, and ruling it out is a far simpler step than working through a dementia evaluation.
