What is a common sign of hypoxia?

Cyanosis of the skin is a common sign of hypoxia because it indicates that there is inadequate oxygenation of the blood. When the body’s tissues do not receive enough oxygen, hemoglobin, which normally carries oxygen in the blood, can become less saturated. This lack of oxygen can cause the blood to take on a bluish tint, particularly noticeable in areas with high capillary networks like the lips, fingertips, and nail beds. This visible change in skin color is a physical manifestation of hypoxia and serves as a critical indicator for medical professionals when assessing a patient’s oxygenation status.

In contrast, other options such as increased appetite, elevated blood pressure, and a severe headache are not directly associated with hypoxia. Increased appetite typically does not correlate with low oxygen levels, and while elevated blood pressure may occur due to various physiological stressors, it is not an exclusive sign of hypoxia. A severe headache could be associated with other conditions, including migraines or tension headaches, and is not a direct indicator of hypoxia.