Soroche, the local term for altitude sickness, is the body’s physiological response to reduced oxygen levels at high altitudes. Understanding it is crucial for a safe experience in mountainous areas.
Understanding Soroche
At higher elevations, atmospheric pressure decreases, meaning fewer oxygen molecules are available with each breath, leading to less oxygen entering the bloodstream. The body attempts to compensate through acclimatization, a process involving increased breathing and heart rate to deliver more oxygen and, over time, producing more red blood cells. This adaptive process takes several days. Rapid ascent prevents sufficient acclimatization, causing symptoms as the body struggles with reduced oxygen. Susceptibility varies, with speed of ascent and altitude playing a role.
Recognizing the Symptoms
Symptoms of soroche can range from mild discomfort to severe, potentially life-threatening conditions.
Mild Symptoms
Mild acute mountain sickness (AMS), the most common form, often resembles a hangover and typically appears within 12 to 24 hours of reaching a higher elevation. Common mild symptoms include headache, nausea, dizziness, fatigue, shortness of breath upon exertion, loss of appetite, muscle aches, and trouble sleeping. These usually resolve within a day or two as the body adjusts.
Severe Symptoms
More severe forms of altitude sickness, though less common, demand immediate attention. High Altitude Pulmonary Edema (HAPE) involves fluid in the lungs, causing severe shortness of breath at rest, a persistent cough (possibly with pink sputum), chest tightness, and a rapid heart rate. High Altitude Cerebral Edema (HACE) occurs when fluid causes the brain to swell. Symptoms include a severe headache, confusion, loss of coordination (ataxia) which can manifest as difficulty walking in a straight line, altered mental status, and potentially coma. Both HAPE and HACE are medical emergencies that can progress rapidly and can be fatal within hours if not treated promptly.
Preventing Soroche
Minimizing the risk of soroche largely depends on allowing the body adequate time to adjust to the altitude.
Gradual Acclimatization
Gradual ascent is the most effective prevention. Above 8,000 feet (2,438 meters), increase sleeping altitude by no more than 1,000 to 1,640 feet (300 to 500 meters) per day. Incorporate rest days every 3,000 feet (915 meters) gained. If flying directly, spend a day or two at a moderate elevation before ascending higher.
Lifestyle Adjustments
Maintaining proper hydration is important; drink plenty of water throughout the day. Avoid alcohol, tobacco, and heavy meals, especially initially, as they can exacerbate symptoms or impair acclimatization.
Prophylactic Medication
For higher risk individuals or rapid ascents, prophylactic medications like acetazolamide (Diamox) can be considered. This prescription medication speeds up acclimatization and should typically be started a day before ascending.
Managing Soroche
If symptoms of soroche develop, prompt action can prevent them from worsening.
Mild Symptom Management
For mild symptoms, resting at the current altitude, staying hydrated, and taking over-the-counter pain relievers like ibuprofen or acetaminophen for headaches can provide relief. It is important to avoid further ascent until symptoms have completely subsided.
Severe Symptom Management
If symptoms worsen or become severe, immediate descent to a lower altitude is the primary and most effective treatment. A descent of at least 984 feet (300 meters) to 3,281 feet (1,000 meters) often leads to significant improvement. Medical attention is necessary if severe symptoms like severe shortness of breath at rest, confusion, or inability to walk are present, as these may indicate HAPE or HACE. In such emergencies, supplemental oxygen and certain prescription medications may be administered, but rapid evacuation to a medical facility at a lower elevation remains paramount.