Denver, known as the “Mile High City,” sits at an elevation of approximately 5,280 feet (1,609 meters) above sea level. For visitors and new residents arriving from lower elevations, this moderate altitude presents a physiological challenge requiring a period of adjustment. Successfully navigating this transition ensures a safe and comfortable experience. This guide provides practical strategies for acclimatizing to the elevation changes in the Denver area.
How Altitude Affects the Body
The primary cause of altitude-related symptoms is the change in atmospheric pressure, not the percentage of oxygen in the air. Although the air still contains 21% oxygen, the lower pressure means each breath delivers fewer oxygen molecules to the bloodstream. This leads to hypoxia, or reduced oxygen availability to the body’s tissues. Denver’s moderate altitude means the air contains about 20% less oxygen than at sea level. The body compensates by increasing the breathing rate and heart rate. A common reaction is Acute Mountain Sickness (AMS), which can feel similar to a hangover. Mild symptoms include headache, fatigue, nausea, and shortness of breath upon exertion. These symptoms typically manifest within 6 to 10 hours of arrival and resolve naturally within 24 to 48 hours as the body begins to acclimatize.
Essential Strategies for Acclimatization
The most effective strategy for adjustment is hyper-hydration, which should start before arrival. The air at altitude is notably drier, and the increased respiratory rate causes the body to lose fluid faster than at sea level. Aim to consume three to four quarts (or liters) of water per day during the first few days to counter this accelerated fluid loss.
Managing physical activity is also a significant factor in successful acclimatization. Take the first 24 to 48 hours easy, avoiding strenuous exercise or heavy lifting. Pushing the body while it is stressed from hypoxia can worsen AMS symptoms. Light walking is preferable to lying down, as respiration decreases during sleep, potentially slowing the acclimatization process.
Dietary choices influence how well the body adapts. Increasing your intake of complex carbohydrates can be beneficial, with some recommendations suggesting up to 70% of calories from carbohydrates. Carbohydrates require less oxygen to metabolize compared to fats and proteins, making them a more efficient energy source at altitude to fuel the body’s increased metabolic demands.
Strictly limit or completely avoid alcohol and excessive caffeine for the first few days. Alcohol acts as a diuretic, accelerating dehydration and masking altitude sickness symptoms like dizziness and nausea. Caffeine also contributes to fluid loss, hindering the necessary hydration required for adjustment. Avoiding depressants, including some sleeping pills, is also wise, as they can suppress the respiratory drive during sleep.
Altitude can disrupt sleep, causing insomnia or periodic breathing, where brief pauses in breath occur throughout the night. Maintaining a consistent sleep schedule and ensuring your body is well-rested is important. Much of the body’s adaptive process occurs during recovery, allowing it to better ramp up red blood cell production and other long-term physiological changes.
Recognizing and Responding to Severe Altitude Sickness
While rare at Denver’s elevation, Acute Mountain Sickness can progress into two severe, life-threatening conditions: High Altitude Cerebral Edema (HACE) and High Altitude Pulmonary Edema (HAPE). Recognizing the warning signs of these conditions is essential because they require immediate action.
HACE is severe swelling of the brain, typically presenting as a worsening of AMS symptoms. Warning signs include severe confusion, irrational behavior, extreme lethargy, and loss of coordination known as ataxia. The inability to walk a straight line heel-to-toe is a simple test for ataxia, suggesting immediate medical consultation is required.
HAPE involves a buildup of fluid in the lungs, identifiable by breathing difficulties. Be alert for severe shortness of breath even when resting, a persistent, wet cough, or a cough that produces pink or frothy sputum. Both HACE and HAPE can progress rapidly, sometimes within hours, and are medical emergencies.
If any severe symptoms develop, immediate medical attention is necessary. The definitive treatment for both is descent to a lower elevation. Never attempt to “tough out” these severe symptoms, as a delay in treatment can have dire consequences.