Is it normal for healthy person to have low oxygen on flight? dipped down to 91-89 on my last flight and had a headache. worried about undiagnosed pe.

Stop: Why are you checking your oxygen on a flight? If it constantly stays below 89 for more than 5 min AND you feel short of breath, have chest pain, or pain and swelling in your legs then start to worry and see a doctor. Portable pulse oximeter readings bounce around all the time- it is usually from motion artifact and not a true reading. Try browsing the in-flight magazine to pass the time...

Unusual: It is highly unusual for oxygen saturation to drop in flight since the ambient oxygen concentration in the cabin is maintained. It is not uncommon, however, for an individual to experience blood clot in the lower extremities, especially during long flights. It is most likely a sign if PE. Therefore, please seek medical consult for doppler ultrasound of the legs to check for venous thrombosis.

Oxygen saturation: Without any health problem oxygen saturations should not drop during flight. If you are worried about PE please see doctor.