The human body responds to changes in elevation by adjusting to reduced atmospheric pressure and lower oxygen availability. When traveling to a higher location, the air still contains 21% oxygen, but the overall pressure pushing that oxygen into the lungs is diminished. While Denver is famously nicknamed the “Mile High City,” its elevation is not high enough to cause serious altitude sickness in most people. Visitors may still notice certain physiological effects as their body acclimates to the thinner air.
Denver’s Elevation and the Sickness Threshold
Denver sits at an official elevation of 5,280 feet (1,609 meters) above sea level, placing it in the moderate altitude range. Medical definitions typically classify high altitude as beginning at 8,000 feet (2,438 meters), with the risk of Acute Mountain Sickness (AMS) becoming significant. Because AMS is uncommon below this 8,000-foot threshold, true, severe altitude sickness is extremely rare in the city itself. However, the elevation is sufficient to cause subtle, immediate changes in unacclimated individuals, primarily due to the lower partial pressure of oxygen. Upon arrival, the body’s initial response involves increasing heart rate and respiration to compensate for the lower oxygen level in the blood.
Common Signs of Altitude Adjustment
The physical changes visitors experience in Denver are often best described as “altitude adjustment” rather than sickness, as they are generally mild and transient. Many people report a slight, persistent headache or unusual fatigue and sluggishness during the first day or two.
Shortness of breath may become apparent during even minor physical exertion, such as walking up a flight of stairs. Some visitors experience mild digestive upset, including a lack of appetite or slight nausea. Disturbed sleep patterns, such as waking up frequently or restless nights, are also minor effects of the body working harder to maintain oxygen saturation.
These symptoms are temporary and usually resolve within 24 to 48 hours as the body naturally begins its acclimatization process. However, any development of severe symptoms, such as persistent vomiting, confusion, or difficulty breathing while at rest, warrants immediate medical attention.
Essential Acclimatization Strategies
The most effective strategy for minimizing the effects of Denver’s elevation is aggressive hydration, given the region’s arid climate and the increased respiratory water loss. Experts recommend significantly increasing water intake, aiming for three to four liters of water per day during the initial adjustment period. Maintaining this level of hydration helps to mitigate a primary driver of altitude discomfort.
Limiting or entirely avoiding alcohol and excessive caffeine for the first 24 to 48 hours is also highly recommended. Both substances act as diuretics, accelerating dehydration and complicating the body’s efforts to acclimate to the reduced oxygen environment.
Furthermore, visitors should consciously pace their physical activity, avoiding strenuous exercise immediately upon arrival. Allowing the body a day or two of reduced activity lets the respiratory and circulatory systems begin their necessary adjustments.
Another important consideration is sun protection. The thinner atmosphere filters less solar radiation, leading to an estimated 20 to 30 percent increase in UV exposure compared to sea level. This intense sun, combined with the dry air, can quickly exacerbate dehydration and lead to sunburn, making the liberal application of broad-spectrum sunscreen and wearing sunglasses an important part of the acclimatization plan.