Descending to a lower altitude is the most important and effective treatment for High-Altitude Cerebral Edema. The increased oxygen at lower elevations helps reduce brain swelling and quickly improves symptoms such as confusion, poor coordination, and severe headache. Even a descent of 500–1,000 meters (1,600–3,300 feet) can make a significant difference. Descent should begin immediately once HACE is suspected, without waiting for symptoms to worsen. Supplemental oxygen and rest during or after descent further support recovery and prevent permanent brain injury.