Restlessness, anxiety, irritability, dyspnea, and tachycardia are signs of which stage of hypoxia?

• A. Late hypoxia
• B. No symptoms
• C. Early hypoxia
• D. Hyperoxia

Answer: (C)

When tissues start to lack enough oxygen, the body first tries to compensate. Restlessness, anxiety, and irritability come from the brain sensing distress, while dyspnea and tachycardia reflect the heart and lungs working harder to deliver oxygen. These are hallmarks of early hypoxia, when the patient may still appear alert but is showing signs of the body’s swift attempt to cope with low oxygen. If hypoxia progresses, mental status changes such as confusion or lethargy develop, and skin color can shift toward blue (cyanosis) in later stages. Hyperoxia isn’t a stage of hypoxia at all, and no symptoms would indicate oxygen levels are not yet low enough to trigger these compensatory signs.