YES — untreated moderate to severe obstructive sleep apnea (OSA) increases the risk of serious, potentially fatal health problems. It may not directly “cause” sudden death every time, but it raises the chance of life‑threatening events over time.
Why and how it can be dangerous
- Repeated oxygen drops: During apnoeas (pauses in breathing) oxygen saturation falls and carbon dioxide rises. Chronic intermittent low oxygen stresses the heart, brain and other organs.
- Cardiovascular strain: OSA is strongly linked with high blood pressure, coronary artery disease, heart attack and stroke. The repeated surges in heart rate and blood pressure during sleep increase long‑term cardiovascular risk.
- Arrhythmias: Apnoeas can provoke abnormal heart rhythms (atrial fibrillation, ventricular arrhythmias). Dangerous arrhythmias may occasionally lead to sudden cardiac death, especially in people with existing heart disease.
- Heart failure: OSA contributes to development and worsening of heart failure. People with untreated OSA and heart disease have poorer outcomes.
- Daytime risks: Severe daytime sleepiness raises the risk of road traffic accidents and workplace incidents, which can be fatal.
- Metabolic and inflammatory effects: OSA promotes insulin resistance, systemic inflammation and atherosclerosis — all increasing long‑term mortality risk.
Who is at highest risk
- People with moderate to severe OSA (measured by apnoea–hypopnoea index, AHI).
- Those with existing cardiovascular disease, uncontrolled hypertension, diabetes, obesity, or prior stroke.
- Older adults and people with significant daytime sleepiness.
- Someone with very low overnight oxygen levels or frequent prolonged apnoeas.
How much does it increase risk?
- Studies show untreated OSA is associated with higher risks of cardiovascular events and mortality. Exact numbers vary by study and population. Overall, treatment of OSA reduces some of these risks, particularly CPAP therapy in adherent patients.
Signs you should seek help now
- Loud, frequent snoring with witnessed pauses in breathing.
- Excessive daytime sleepiness (falling asleep unintentionally).
- Morning headaches, poor concentration, mood changes.
- Waking gasping or choking.
- Known heart disease plus symptoms suggestive of OSA.
What to do
- See your GP or an NHS clinic if you suspect OSA. They may screen you (questionnaires, pulse oximetry) and refer for sleep testing.
- Diagnosis: home sleep apnoea testing or in‑lab polysomnography to measure apnoeas, oxygen levels and sleep quality.
- Treatments:
- CPAP (continuous positive airway pressure) is the most effective for moderate–severe OSA.
- Mandibular advancement devices for milder cases or CPAP intolerance.
- Weight loss, positional therapy, avoiding alcohol/sedatives before bed.
- Surgery in selected cases.
- Manage cardiovascular risk: treat high blood pressure, cholesterol, diabetes and stop smoking.
Bottom line Sleep apnoea is not trivial. Left untreated, especially when moderate or severe, it substantially raises the risk of fatal cardiovascular events and accidents. Early diagnosis and effective treatment markedly reduce those risks.
If you’re worried about yourself or a loved one, book an appointment with your GP. Dozywave also focuses on improving sleep hygiene and comfort; while our products don’t treat OSA, combining good sleep routines with medical assessment can improve overall sleep health.