Sleep apnea: what you need to know.
Obstructive sleep apnea is the most common form of sleep-disordered breathing — and roughly 80% of moderate-to-severe cases are never diagnosed. Understanding it is the first step toward getting your nights back.
What is obstructive sleep apnea?
Obstructive sleep apnea (OSA) occurs when the muscles of the throat relax during sleep and the soft tissues of the airway partially or completely collapse. Airflow to the lungs is blocked — sometimes hundreds of times per night — cutting oxygen delivery to the brain and vital organs.
Each apnea event — a pause in breathing lasting ten seconds or longer — triggers a stress response. Cortisol surges, blood pressure spikes, and the heart works harder to keep blood moving. Repeated nightly for years, that physiological stress drives some of the most serious chronic diseases of our era.
The troubling part: the primary symptom happens while you're unconscious. Bed partners are usually the first to notice.
AHI — how severity is measured
The Apnea-Hypopnea Index (AHI) counts breathing events per hour of sleep. Mild OSA is 5–14 events an hour, moderate is 15–29, and severe is 30 or more. Even mild OSA warrants evaluation — the health consequences are cumulative.
RDI — the more complete picture
The Respiratory Disturbance Index (RDI) goes further, counting respiratory effort-related arousals (RERAs) — brief disruptions that fragment sleep and fire the stress response without meeting the full apnea threshold. A patient with a low AHI but high RDI can still have significant sleep-disordered breathing that goes untreated when RDI is ignored. We evaluate both.
A hypopnea only counts as an event if oxygen drops by a defined threshold. The American Academy of Sleep Medicine recommends 3% — but many insurers require a 4% drop before an event counts. That stricter scoring systematically lowers the reported AHI, makes sleep apnea look milder than it is, and gives a basis to deny treatment coverage. If your study was scored at 4%, you may be under-diagnosed. We read results in clinical context, not through an insurer’s lens.
Recognizing the symptoms
The signs span night and day, and because they build gradually, many patients normalize them as “just the way I am.” If several of these sound familiar, an evaluation is warranted:
- Loud, chronic snoring
- Gasping or choking during sleep
- Waking unrefreshed despite adequate sleep hours
- Excessive daytime sleepiness
- Morning headaches
- Difficulty concentrating or memory problems
- Frequent nighttime urination
- Acid reflux or GERD
- Irritability and mood changes
- High blood pressure that doesn't respond to medication
The health consequences of untreated OSA
Higher risk of cardiovascular events with untreated OSA.
Of diabetics have obstructive sleep apnea.
Higher risk with untreated obstructive sleep apnea.
More likely in patients with untreated OSA.
How it’s diagnosed
Diagnosis requires a sleep study — a formal polysomnogram in a sleep lab, or a home sleep apnea test for appropriate candidates. These measure breathing, oxygen saturation, heart rate, brain activity, and movement through the night. At Symmetry Modern Dentistry, we collaborate with board-certified sleep physicians, facilitate testing, and read the results against your oral and airway anatomy — including cone-beam CT imaging that shows the three-dimensional structure of the airway and its collapse pattern.
Treatment doesn’t have to mean CPAP
Depending on severity and anatomy, candidates may do well with oral appliance therapy, positional therapy, weight management, surgical options, or a combined approach — see CPAP alternatives for the full landscape.
Concerned about sleep apnea?
Two minutes of honest answers tells you whether an evaluation is the right next step.