When a stressful situation is encountered in flight, an abnormal increase in volume of air breathed in and out can cause which condition?

• A. Hyperventilation
• B. Hypoxia
• C. Decompression sickness
• D. Fatigue

Answer: (A)

When stressed in flight, breathing can become rapid and deep, which is hyperventilation. Blowing off carbon dioxide faster than it’s produced lowers the CO2 in your blood, causing a rise in blood pH (respiratory alkalosis). That shift narrows the blood vessels in the brain, reducing cerebral blood flow, which can lead to dizziness, lightheadedness, tingling around the mouth and fingers, and even confusion or faintness. Despite feeling like you can’t get enough air, the issue isn’t a lack of oxygen but excessive CO2 loss, which can impair judgment and coordination and be dangerous in the cockpit. This behavior is different from hypoxia (insufficient oxygen), decompression sickness (gas bubbles from rapid pressure change), or fatigue (general tiredness). To recover, slow and regulate breathing to restore normal CO2 levels, stay calm, and regain control of the situation.