Sleep apnea is one of the most underdiagnosed medical conditions in adults. Estimates suggest that approximately 26% of adults aged 30–70 have obstructive sleep apnea (OSA) — yet 80% of cases go undiagnosed. The consequence of missing the diagnosis is significant: untreated OSA is associated with hypertension, stroke, type 2 diabetes, cardiovascular disease, cognitive decline, and dramatically impaired daily functioning. If you recognise the symptoms described here, getting tested is straightforward and increasingly affordable.

What Is Sleep Apnea?

Sleep apnea is characterised by repeated episodes of partial or complete upper airway collapse during sleep. The three main types are:

Severity is measured by the Apnea-Hypopnea Index (AHI) — the average number of apnea events per hour of sleep. Mild OSA: 5–15 events/hour. Moderate: 15–30 events/hour. Severe: 30+ events/hour. Each event causes a brief arousal (usually not remembered) that prevents deep, restorative sleep.

Primary Symptoms of Sleep Apnea

Loud, Persistent Snoring

The most common presentation of OSA. The snoring typically has a characteristic pattern: loud snoring followed by silence (the apnea event) followed by a snort, gasp, or choking sound as breathing resumes. Not everyone with OSA snores, and not everyone who snores has OSA — but this combination is highly predictive. If a partner or roommate has described this pattern, it warrants immediate investigation.

Excessive Daytime Sleepiness (EDS)

Falling asleep during daytime activities — reading, watching TV, sitting in meetings, or even briefly while driving — is the defining functional symptom of sleep apnea. This occurs because the repeated overnight arousals (hundreds per night in severe cases) prevent the deep and REM sleep stages the body needs. Importantly, many people with OSA normalise their daytime sleepiness as "just how I am" — this is a significant diagnostic barrier.

Morning Headaches

Waking with a headache that resolves within an hour or two of being upright is a specific and underappreciated symptom of OSA. During apnea events, oxygen levels fall and carbon dioxide accumulates — CO2 causes cerebral vasodilation, which produces the characteristic morning headache. This symptom is present in approximately 30–40% of OSA patients.

Unrefreshing Sleep

Waking after what should be an adequate night of sleep feeling as though you haven't slept — physically tired, cognitively foggy, physically stiff. Because deep sleep is repeatedly terminated by apnea events, the restorative phases of sleep are chronically incomplete. This symptom is often what first prompts people to investigate their sleep quality.

Waking With Dry Mouth or Sore Throat

OSA frequently causes mouth breathing (as the body attempts to maintain airway patency during obstruction), leading to significant drying of the mouth and throat. A consistently dry mouth on waking, especially when combined with other symptoms, is a useful indicator.

Nocturia (Waking to Urinate)

Less well known but well-documented: OSA causes increases in atrial natriuretic peptide (ANP) during apnea events, which promotes urine production. Many adults who attribute nighttime urination to their age or bladder have their sleep apnea as the primary driver. Effective CPAP treatment reduces nocturia in many patients.

Cognitive Impairment and Mood Changes

Difficulty concentrating, memory problems, irritability, and low mood are common in untreated OSA — a direct consequence of chronic sleep fragmentation and intermittent hypoxia. These cognitive effects are often the most disabling aspect of OSA for working adults.

Risk Factors for Sleep Apnea

How to Get Tested

Testing for sleep apnea has become much more accessible. Options include:

Speak with your primary care physician, describe your symptoms, and request a referral for an at-home sleep test. Given how common OSA is and how significantly it impairs quality of life and health, this is one of the highest-value medical investigations most adults over 40 can undertake.

For related information see our article on signs of sleep apnea and our guide on natural remedies for sleep apnea.

Medical disclaimer: This article is for informational purposes only. If you suspect you have sleep apnea, consult a qualified healthcare provider. Sleep apnea is a medical condition requiring professional diagnosis and management.


About the author: Morgan Wells is a certified sleep analyst and wellness writer with over a decade of experience in behavioral sleep health. Learn more about Morgan.