No, breathing into a paper bag is dangerous and will worsen hypoxia at altitude
Breathing into a paper bag when you already lack oxygen will make things worse, not better—it can drop your oxygen levels to dangerously low levels and should never be used for altitude sickness or any condition where oxygen is already low. 1
Why Paper Bag Rebreathing Is Harmful in Hypoxia
The paper bag technique was historically used for anxiety-induced hyperventilation (where oxygen levels are normal but CO2 is too low). However, when applied to someone who is already hypoxic:
- Oxygen drops precipitously: Research shows that after just 30 seconds of paper bag rebreathing, oxygen drops by an average of 16 mmHg, reaching drops of 26-42 mmHg by 3 minutes 1
- Fatal outcomes documented: Three deaths occurred when this technique was mistakenly applied to patients who were hypoxemic or had cardiac ischemia 1
- At altitude, you're already hypoxic: Your baseline oxygen is critically low, so further reducing it by rebreathing exhaled air (which is oxygen-depleted) creates a medical emergency
What Actually Works for Altitude Hypoxia
Immediate interventions:
- Descend immediately if symptoms are severe—this is the definitive treatment
- Supplemental oxygen if available (consider for altitudes >1500-2000m in symptomatic patients) 2
- Acetazolamide improves oxygen saturation while treating altitude sickness symptoms 2
Novel approaches with evidence:
- Positive expiratory pressure (PEP) devices can increase oxygen saturation by 3.5-4.7% at altitude 3
- CPAP at 10 cmH2O significantly improves oxygen saturation both at rest and during exertion (83.8% vs 78.7% during exercise) 4
- Low-dose CO2 inhalation (2.5%) through specialized devices increases both PaCO2 and PaO2, but requires precise delivery equipment 5
Critical Pitfall to Avoid
The confusion arises because paper bag rebreathing increases CO2, and some might think "CO2 helps at altitude" based on newer research 5. However, the uncontrolled CO2 increase from a paper bag comes at the cost of severe oxygen depletion—the exact opposite of what you need when already hypoxic.