Which symptom indicates significant hypoxia?

Significant hypoxia refers to a condition where there is a deficiency of oxygen reaching the tissues in the body. One of the key symptoms associated with significant hypoxia is excessive sleepiness or fatigue. This occurs because the body is not receiving enough oxygen to perform its normal functions efficiently, leading to fatigue and a general sense of malaise. The brain, which is highly sensitive to oxygen levels, often signals the body to slow down, resulting in feelings of tiredness and a need for rest.

The other options represent normal or unrelated responses to hypoxia. For instance, normal vision would not indicate any issues with oxygen levels, as it suggests that the eyes and brain are functioning adequately. Increased appetite generally does not correlate with hypoxia; instead, individuals may experience a reduction in appetite due to nausea or overall unwellness. Heightened reflexes are usually associated with stress responses or increased arousal, rather than a direct sign of hypoxia, which typically manifests in decreased responsiveness or lethargy. Thus, excessive sleepiness or fatigue stands out as a clear indicator of significant hypoxia.