What is Hypoxia?

• A. Increased blood oxygen levels
• B. Reduced levels of oxygen in the blood
• C. A type of pressure change
• D. A disease

Answer: (B)

Hypoxia is a condition in which the body's tissues don’t receive enough oxygen to meet their needs. In aviation, this often comes from the reduced oxygen in the blood as you ascend, so less oxygen is delivered to cells. That’s why describing it as reduced levels of oxygen in the blood is the best match. The other ideas don’t define hypoxia: more oxygen in the blood is hyperoxia, a pressure change isn’t the definition (though pressure changes can cause hypoxia), and hypoxia isn’t a disease, but a state that can result from various causes.