What are the causes and treatments for a scratchy throat in a patient using Continuous Positive Airway Pressure (cPAP) therapy?

Scratchy Throat After Staying on CPAP

Add heated humidification to your CPAP device immediately—this is the most evidence-based intervention to eliminate dry and scratchy throat symptoms during PAP therapy. 1

Primary Cause and Solution

The scratchy throat you're experiencing results from inhaled air dryness during CPAP therapy, which is significantly worsened by mouth breathing or mouth leaks during sleep. 2, 3

Heated Humidification (First-Line Treatment)

The American Academy of Sleep Medicine guidelines strongly recommend using heated humidification with PAP devices to reduce upper airway side effects. 1 Meta-analyses demonstrate clinically significant reduction in:

• Dry mouth/throat 1
• Sore throat 1
• Nasal congestion 1
• Dry nose 1

Heated humidification increases the relative humidity of inspired air from approximately 43% (with mouth leaks) to 64%, and from 60% to 81% when the mouth is closed. 3 This prevents the upper airway dryness that causes your scratchy throat sensation.

Secondary Contributing Factor: Mouth Leaks

If heated humidification alone doesn't fully resolve your symptoms, mouth leaks are likely contributing. 4, 5, 2

Evidence on Mouth Leaks

Mouth leaks during nasal CPAP cause:

• High unidirectional nasal airflow that increases nasal resistance from 2.21 to 7.52 cm H₂O/L/s 2
• Sleep fragmentation with arousals in 52.7% of leak episodes and awakenings in 38.6% 4
• Persistent upper airway dryness despite humidification 4, 3

Solutions for Mouth Leaks

Switch from a nasal mask to a nasal/intranasal interface first, as these have fewer side effects than oronasal masks. 1 If mouth breathing persists:

1. Try a chin strap to keep your mouth closed during sleep 1
2. If the chin strap fails, switch to a full-face (oronasal) mask 1, 3

Full-face masks completely prevent relative humidity changes during mouth breathing (maintaining 84% humidity with mouth open vs. 39% with nasal mask and mouth leak). 3 However, nasal masks generally have better adherence and fewer side effects, so exhaust simpler solutions first. 1

Implementation Algorithm

1. Add heated humidification immediately (if not already using) 1
2. Ensure proper mask fit to minimize unintentional leaks 1
3. If symptoms persist after 1-2 weeks with humidification:
   • Try a chin strap if using a nasal mask 1
   • Consider switching to a full-face mask if chin strap ineffective 1, 3
4. Monitor for "rain-out" (condensation in tubing)—use a heated hose if this occurs 1

Common Pitfalls to Avoid

• Don't overtighten the mask headgear attempting to reduce leaks, as this causes skin breakdown and worsens compliance 1
• Don't ignore persistent symptoms—mouth leaks occur in most CPAP users and contribute to treatment failure 4, 5
• Don't assume your CPAP device's leak report is accurate—device reports detect only 29.6% of actual leak episodes identified on polysomnography 4
• Don't use distilled water inconsistently—heated humidification requires regular maintenance and water refills 1

When to Seek Further Evaluation

If scratchy throat persists despite heated humidification and addressing mouth leaks, contact your sleep medicine provider to assess for: 1

• Inadequate CPAP pressure settings
• Mask interface problems requiring professional refit
• Need for polysomnography to evaluate treatment efficacy