Obstructive Sleep Apnea (OSA) is a common but serious sleep-related breathing disorder in which the upper airway collapses or becomes blocked during sleep, causing repeated pauses in breathing. Each pause, known as apnea, can last from a few seconds to over a minute and may occur dozens or even hundreds of times per night.
This article provides an in-depth look at OSA pathophysiology, causes, symptoms, risk factors, complications, and treatment, along with practical patient education strategies.
Pathophysiology of Obstructive Sleep Apnea
OSA occurs when the muscles of the pharynx and tongue relax excessively during sleep, causing airway narrowing or complete collapse.
During normal breathing, air flows freely through the nose and mouth into the lungs. In OSA, the airway is obstructed due to:
- Tongue falling back into the throat
- Soft palate collapse
- Excess tissue in the pharynx due to obesity
The result: airflow stops despite continued respiratory effort. The brain senses low oxygen levels (hypoxia) and briefly wakes the person to reopen the airway — disrupting the normal sleep cycle.
Causes and Risk Factors
A helpful memory trick: OSA = Obese, Sedatives, Alcohol
Major Causes
- Obesity or overweight: Extra fat around the neck narrows the airway
- Sedatives before bed: Drugs like benzodiazepines and opiates relax airway muscles excessively
- Alcohol: Increases muscle relaxation and worsens airway collapse
Other Risk Factors
- Male gender
- Age over 40
- Family history of OSA
- Large neck circumference (>17 inches in men, >16 inches in women)
- Nasal congestion or chronic rhinitis
- Smoking
Signs and Symptoms
Daytime Symptoms
- Morning headaches
- Daytime sleepiness
- Chronic fatigue
- Irritability, mood swings, or depression
- Difficulty concentrating
Nighttime Symptoms
- Loud, chronic snoring
- Witnessed episodes of apnea (pauses in breathing)
- Gasping or choking during sleep
- Restless sleep or frequent awakenings
Complications of Untreated OSA
If left untreated, OSA can cause:
- Hypertension – due to repeated surges in blood pressure at night
- Cardiac arrhythmias – such as atrial fibrillation
- Stroke
- Heart failure
- Type 2 diabetes – linked to insulin resistance
- Daytime accidents – due to drowsiness and impaired concentration
Diagnosis
- Polysomnography (Sleep Study) – Gold standard; measures breathing patterns, oxygen levels, and brain activity during sleep
- Home Sleep Apnea Testing (HSAT) – Portable alternative for selected patients
- Epworth Sleepiness Scale – Screening tool for daytime sleepiness severity
Management and Interventions
1. Lifestyle Modifications
- Weight loss – Even a 10% weight reduction can significantly improve OSA severity
- Regular exercise – Improves respiratory muscle tone
- Avoid alcohol – Especially before bedtime
- No sedatives – Unless prescribed for another condition under medical supervision
- No napping during the day – Helps consolidate nighttime sleep
- No eating close to bedtime
2. CPAP Therapy (Continuous Positive Airway Pressure)
- Uses a mask and air pump to deliver pressurized air into the airway
- Prevents collapse of pharynx and tongue during sleep
- Considered first-line treatment for moderate to severe OSA
Key CPAP Tips:
- Ensure proper mask fit
- Adjust strap tightness for comfort and seal
- Clean mask regularly to prevent infection
3. BiPAP Therapy (Bilevel Positive Airway Pressure)
- Alternative for patients not compliant with CPAP
- Provides two pressure settings — higher during inhalation, lower during exhalation
- More comfortable for some patients, especially those with high CPAP pressure needs
4. Other Interventions
- Oral appliances – Reposition jaw and tongue to keep airway open
- Surgery – Uvulopalatopharyngoplasty (UPPP) or maxillomandibular advancement for selected cases
- Positional therapy – Avoiding sleeping on the back
Quick Reference Table: OSA Overview
| Feature | Description |
|---|---|
| Cause | Airway collapse due to obesity, sedatives, alcohol |
| Daytime Symptoms | Fatigue, headaches, irritability |
| Nighttime Symptoms | Snoring, apnea episodes, choking |
| Diagnosis | Sleep study (polysomnography) |
| First-Line Treatment | CPAP therapy |
| Alternative | BiPAP, oral appliances, surgery |
| Prevention | Weight loss, avoid alcohol/sedatives |
Frequently Asked Questions (FAQs)
1. Can OSA be cured?
Mild cases may improve with weight loss, lifestyle changes, or oral appliances. Severe cases usually require CPAP or surgical intervention.
2. Is snoring always a sign of OSA?
No. While most OSA patients snore, not all snorers have OSA. Diagnosis requires a sleep study.
3. How quickly does CPAP work?
Many patients notice improvement in sleep quality and daytime alertness within a few nights.
4. What happens if I stop CPAP?
Symptoms and risks (like hypertension and arrhythmia) return quickly, often within days.
5. Can children have OSA?
Yes, commonly due to enlarged tonsils or adenoids, and it requires pediatric evaluation.
