- OSA is when the airway repeatedly collapses during sleep — stopping or severely reducing airflow, sometimes hundreds of times per night
- Overweight and obesity are among the most common causes, due to excess fat tissue around the neck and chest
- OSA causes poor-quality sleep and places serious strain on the cardiovascular system
- Treatment includes weight loss, CPAP devices, and reducing alcohol intake — weight loss is one of the most effective long-term interventions
- If you suspect you have OSA, a formal sleep study is needed for diagnosis — speak to your GP or MedSurg doctor
What Is Obstructive Sleep Apnoea?
Obstructive Sleep Apnoea (OSA) is the most common form of sleep apnoea. It occurs when the muscles of the throat relax during sleep, causing the airway to narrow or close completely — interrupting the normal flow of air into the lungs. When this happens, oxygen levels in the blood fall and carbon dioxide levels rise. The brain detects this and briefly wakes the body to reopen the airway — a process that can repeat hundreds of times each night, severely disrupting sleep quality.
There are two distinct degrees of airway obstruction:
The airway is almost completely closed and very little air is moving through — significantly reducing airflow but not stopping it entirely.
The airway is completely blocked and no air is moving through — breathing temporarily stops until the brain triggers an arousal response.
Symptoms of OSA
OSA is significantly underdiagnosed — many people live with it for years without knowing. Common symptoms include:
Cardiovascular Risks of Untreated OSA
Beyond poor sleep quality, untreated OSA places serious and sustained strain on the cardiovascular system. Each apnoea event triggers a stress response — a surge in adrenaline, a spike in blood pressure, and a reduction in blood oxygen — that, repeated hundreds of times per night over years, causes cumulative damage:
Nocturnal blood pressure spikes prevent the normal overnight drop that protects cardiovascular health
Repeated oxygen drops and pressure changes strain the heart muscle over time
Disrupted blood flow and raised blood pressure increase stroke risk significantly
OSA directly disrupts the heart's electrical system, increasing AF risk and stroke risk
Chronic inflammation and blood pressure changes accelerate arterial narrowing
The cumulative cardiovascular burden of severe untreated OSA raises heart attack risk substantially
The Link Between Obesity and OSA
Overweight and obesity are among the most significant risk factors for OSA. Excess adipose (fat) tissue around the neck and chest narrows the upper airway and increases its tendency to collapse during sleep. This is why OSA is far more prevalent in people living with obesity — and why weight loss is one of the most effective long-term treatments available.
OSA is also closely related to Obesity Hypoventilation Syndrome (OHS) — a more severe breathing condition where excess weight impairs daytime ventilation as well. Many patients with OHS also have OSA.
Treatment Options
The most effective long-term treatment for obesity-related OSA. Significant weight loss reduces the fat tissue compressing the airway — often dramatically reducing the severity of OSA and in some cases resolving it entirely.
Continuous Positive Airway Pressure (CPAP) devices deliver a constant stream of pressurised air through a mask, keeping the airway open during sleep. Highly effective for managing OSA symptoms and cardiovascular risk — prescribed by a Sleep Physician following a formal sleep study.
Alcohol relaxes the throat muscles and worsens airway collapse during sleep. Reducing or eliminating alcohol — particularly in the hours before bed — can meaningfully reduce OSA severity.
If you suspect you may have OSA, the first step is speaking to your GP or a MedSurg Weight Loss doctor. A formal sleep study is required for diagnosis. If OSA is confirmed, we can support your weight loss journey as a core part of your management — alongside CPAP if indicated. Book an appointment or explore our Medical Weight Loss service.
Medical disclaimer: This article is for general educational purposes only. If you are experiencing symptoms of sleep apnoea, please consult your doctor for assessment and referral for a formal sleep study. Do not stop any prescribed CPAP therapy without medical advice.