Hypoxia: Anemic

Elias recognized the signs just in time. He remembered the flight school analogy: "Anemic hypoxia is like having a full tank of gas but a broken fuel pump". Even though the air around him had enough oxygen, his blood couldn't deliver it.

Elias was a veteran pilot, but he was also recovering from a recent bout of severe anemia. He had been cleared to fly, but today, his body was telling a different story. The Invisible Shortage anemic hypoxia

Surprisingly, he didn't feel breathless. This is the danger of anemic hypoxia; because your lungs are absorbing oxygen fine, your body doesn't always trigger the "gasping" reflex associated with suffocating. You just... fade. The Descent Elias recognized the signs just in time