When traveling to higher elevations, many individuals become concerned about altitude sickness, known as Acute Mountain Sickness (AMS). This condition results from the body’s difficulty adapting to lower oxygen levels and reduced atmospheric pressure at significant altitudes, typically above 8,000 feet (2,400 meters). This article clarifies whether diarrhea is a direct symptom of altitude sickness and explores other common reasons for gastrointestinal distress in high-altitude environments.
Altitude Sickness: Common Symptoms
Altitude sickness manifests with symptoms as the body struggles to acclimatize to reduced oxygen. Common symptoms include headache, nausea, fatigue, dizziness, a general feeling of being unwell, loss of appetite, and trouble sleeping.
While general gastrointestinal upset, such as nausea and loss of appetite, is common with AMS, diarrhea is not typically considered a primary or hallmark symptom. Diarrhea can occur as part of broader gastrointestinal discomfort at high altitudes, often alongside vomiting and abdominal pain. However, isolated or severe diarrhea is usually attributed to other factors rather than being a direct physiological response to altitude itself.
Other Reasons for Diarrhea at High Altitude
Diarrhea at high altitude is common, but often due to factors distinct from altitude sickness. Environmental and physiological changes can contribute to digestive issues. Recognizing these causes helps travelers prepare and manage health.
Dehydration is a frequent cause of digestive upset at high altitudes. The dry, thin air increases fluid loss through respiration, and increased urination also contributes to dehydration. When the body lacks sufficient fluids, proper digestion and stool formation can be impaired, potentially leading to diarrhea.
Dietary changes can also play a role in gastrointestinal issues. Unfamiliar foods or changes in cooking practices can upset the digestive system. Additionally, the lower boiling point of water at high altitudes means foods may require longer cooking times to be thoroughly prepared, potentially increasing the risk of consuming undercooked items.
Food and water contamination are significant concerns, especially in regions with varying sanitation standards. Consuming unpurified water or food prepared without proper hygiene can introduce bacteria like E. coli, Salmonella, or parasites such as Giardia, leading to traveler’s diarrhea. These pathogens are common causes of diarrheal illness regardless of altitude but pose a greater risk when traveling.
Stress and anxiety from travel and adapting to a new environment can impact digestive health. Psychological stress can influence gut motility and function, potentially contributing to symptoms like diarrhea. Furthermore, the body’s response to the physiological stress of high altitude can temporarily alter the gut microbiome, affecting how food is processed and potentially leading to digestive symptoms.
Certain medications, including those sometimes prescribed for altitude sickness prevention, can have gastrointestinal side effects. For example, Acetazolamide, a common medication for AMS, may cause stomach upset or diarrhea in some individuals. Other medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), can also affect the intestinal barrier and contribute to digestive complaints.
When to Seek Medical Attention
While mild digestive issues at high altitude might resolve on their own, certain symptoms warrant immediate medical attention. Seeking professional help promptly can prevent more serious complications, especially in remote or challenging environments.
Medical consultation is advisable if diarrhea becomes severe or persistent, particularly if it is accompanied by blood or pus. Signs of severe dehydration, such as significantly reduced urination, extreme thirst, lethargy, or confusion, also indicate a need for urgent care. These symptoms suggest a more serious underlying issue than typical acclimatization discomfort.
Worsening altitude sickness symptoms alongside diarrhea, such as a severe headache unresponsive to medication, confusion, loss of coordination, or severe shortness of breath at rest, require immediate descent and medical evaluation. A fever accompanying diarrhea is another red flag, as it can signal a bacterial infection that may need specific treatment.
Preventing Gastrointestinal Issues at High Altitude
Taking proactive steps can significantly reduce the risk of experiencing diarrhea and other gastrointestinal problems when ascending to high altitudes. Implementing careful hydration and food safety practices is paramount for maintaining digestive health.
Proper hydration is essential at altitude, as the body loses fluids more rapidly. Aim to drink at least 3 to 4 liters of water daily, increasing intake further with physical activity. Incorporating electrolyte-rich fluids can help replenish salts lost through increased respiration and urination, preventing imbalances.
Strict food safety guidelines are crucial. Following the “boil it, cook it, peel it, or forget it” principle prevents consumption of contaminated food and water. Avoid uncooked foods, unpasteurized dairy products, and untreated tap water. Opt for bottled water or properly purified water sources.
Gradual ascent allows the body to acclimatize, reducing physiological stress and mitigating digestive disturbances. Maintain good personal hygiene, especially frequent handwashing or using an alcohol-based hand sanitizer, to prevent pathogen spread.
Choose familiar, easily digestible foods, particularly those high in carbohydrates, during initial days at altitude. Limit or avoid alcohol and caffeine, as these contribute to dehydration and may exacerbate gastrointestinal discomfort.