Hyperventilation
Hyperventilation: over-breathing from stress. Blows off too much carbon dioxide. Symptoms mimic hypoxia (TC AIM AIR 3.2.3, PHAK ch.17):
- Tingling
- Dizziness, light-headedness
- Coldness
- Tight band around the head
- Cramping and spasms in hands and feet
- Visual impairment
- Paradoxical feeling of not getting enough air
- Continued hyperventilation can cause loss of consciousness
Fix (TC AIM AIR 3.2.3(b)):
- Breathe 100% oxygen if available.
- If symptoms persist, slow breathing to 10-12 breaths/min. Do not breathe deeply.
- Slow, deep breathing into a paper bag also helps when practical.
Hyperventilation vs hypoxia:
| Check | Result | Cite |
|---|---|---|
| Symptoms on oxygen | Hypoxia improves within 3-4 breaths | TC AIM AIR 3.2.3(a) |
| Altitude | Below 8,000 ft, hypoxia unlikely the cause | TC AIM AIR 3.2.3(b) |
- Unsure at altitude: treat for hypoxia too. Check equipment and flow rate first. The two overlap closely (PHAK ch.17).
- Skip diagnosis: start with 100% oxygen (TC AIM AIR 3.2.3).
Trap: confusing hyperventilation (slow your breathing) with hypoxia.
References
- TC AIM AIR 3.2
- FAA Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25)