MOUNTAIN SICKNESS

Mountain sickness, also known as altitude sickness or acute mountain sickness (AMS), is a condition that affects individuals who ascend to high altitudes too quickly. This illness can affect anyone, regardless of physical fitness or previous experiences at high altitudes. It encompasses a range of symptoms that can occur when ascending to higher elevations too quickly.

Causes

Mountain sickness occurs due to the reduced oxygen levels at high altitudes. As you ascend, the air becomes thinner, which means there is less oxygen available for your body to function properly. The rapid change in altitude doesn’t give your body enough time to adjust, leading to various symptoms associated with the condition. While individuals living in moderately high-altitude areas gradually acclimate to this pressure, traveling to significantly higher altitudes requires time for the body to adjust.

Altitude sickness typically becomes a concern above 8,000 feet.

Types of Altitude Sickness

Acute Mountain Sickness (AMS): This is the mildest form and is quite common. Symptoms may resemble a hangover, including dizziness, headache, muscle aches, and nausea.
High-Altitude Pulmonary Edema (HAPE): HAPE involves the accumulation of fluid in the lungs, posing a significant health risk and potentially leading to life-threatening complications. It is the most common cause of death associated with altitude sickness.
High-Altitude Cerebral Edema (HACE): HACE is the most severe form of altitude sickness, characterized by the presence of fluid in the brain. It is also life-threatening and requires immediate medical attention.

Prevalence

Mountain sickness is quite common among hikers, climbers, and travelers visiting high-altitude regions. It generally occurs at elevations above 8,000 feet (2,400 meters). However, susceptibility varies widely among individuals. While some people may experience symptoms at lower altitudes, others might only feel the effects at much higher elevations.

Symptoms

Altitude sickness can manifest in various symptoms, including:

Headache
Dizziness
Nausea
Vomiting
Fatigue and loss of energy
Shortness of breath
Sleep disturbances
Loss of appetite

These symptoms typically emerge within 12 to 24 hours after reaching a higher elevation and tend to improve within a day or two as the body adjusts to the altitude change.

Moderate Altitude Sickness Symptoms

In more moderate cases of altitude sickness, symptoms may become more intense and may not respond to over-the-counter medications. Instead of improving over time, symptoms may worsen, and additional symptoms may arise, including:

Loss of coordination and difficulty walking
Severe, unrelenting headache
Tightness in the chest

Severe Altitude Sickness Symptoms

In severe cases, such as high-altitude pulmonary edema (HAPE) or high-altitude cerebral edema (HACE), symptoms may include:

Confusion
Persistent shortness of breath, even at rest
Inability to walk
Cough producing a white or pink frothy substance
Coma

Risk Factors

Altitude sickness can affect anyone, regardless of their fitness level or health status. Even Olympic athletes are susceptible to it, especially when physically active at high elevations.

Several factors influence the likelihood of developing altitude sickness:

Rate of Ascent: The speed at which you ascend to higher elevations.
Altitude Reached: The altitude attained.
Sleeping Altitude: The elevation at which you sleep.
Previous Experience: Whether you’ve experienced altitude sickness before.
Residence Altitude: The altitude of your place of residence.
Age: Younger individuals are more prone to altitude sickness.
Underlying Health Conditions: While having certain illnesses like diabetes or lung disease doesn’t automatically increase the risk, individuals with sickle cell anemia, COPD, unstable angina, high-risk pregnancies, heart failure, recent heart attacks or strokes, or cystic fibrosis are less likely to tolerate altitude changes.

Diagnosis

Mountain sickness is primarily diagnosed based on symptoms and recent exposure to high altitudes. In some cases, medical professionals might use oximeters to measure oxygen saturation levels in the blood. A significant drop in oxygen levels can indicate severe altitude sickness.

Treatments

Mild Symptoms: If experiencing mild symptoms such as headache and other altitude sickness-related symptoms, consider staying at the current altitude to allow the body to adjust. Rest, stay warm, and stay hydrated. Refrain from ascending further until symptoms subside completely.
Severe Symptoms: In case of severe symptoms or if mild symptoms persist or worsen, descend to a lower elevation promptly. Avoid exertion and seek medical assistance.
Medical Evaluation: Medical evaluation may include chest auscultation, chest X-rays, or brain imaging (MRI or CT scan) to assess fluid accumulation.
Treatment for HACE: High-altitude cerebral edema (HACE) may require treatment with dexamethasone, a steroid medication.
Treatment for HAPE: High-altitude pulmonary edema (HAPE) necessitates supplemental oxygen therapy, medications, and descent to lower altitudes.

It’s essential to prioritize safety and seek medical attention if experiencing severe symptoms or if symptoms persist despite rest and hydration.

Home Care Tips

If you are planning a high-altitude trip, consider the following tips to manage symptoms at home or in a non-medical setting:

Hydrate: Drink plenty of fluids to stay hydrated.
Avoid Alcohol: Alcohol can exacerbate dehydration and symptoms.
Eat Light: Consume easily digestible foods to avoid gastrointestinal discomfort.
Gradual Ascent: Ascend slowly and take regular breaks to allow your body to adjust.
Monitor Symptoms: Keep an eye on symptoms and seek medical help if they worsen.

Prevention

The most effective approach to reduce the risk of altitude sickness is through acclimatization, allowing your body to gradually adjust to changes in air pressure as you ascend to higher elevations.

Acclimatization Guidelines:

Gradual Ascent: Begin your journey below 10,000 feet. If traveling to higher altitudes by air or road, stop at a lower destination for at least a full day before proceeding higher.
Use of Acetazolamide: If unable to acclimatize gradually, acetazolamide can aid in speeding up acclimatization.
Moderate Ascent: When walking, hiking, or climbing above 10,000 feet, ascend no more than 1,000 feet per day. Rest at least a day at every 3,000 feet climbed.
Climb High, Sleep Low: After ascending over 1,000 feet in a day, descend to a lower altitude for sleeping.
Hydration and Nutrition: Drink 3-4 quarts of water daily, ensuring that about 70% of your calories come from carbohydrates.
Avoidance of Substances: Refrain from using tobacco, alcohol, or medications like sleeping pills, especially during the first 48 hours. Caffeine consumption is acceptable if it is part of your regular intake.
Moderate Exercise: Avoid vigorous exercise during the initial 48 hours at higher altitudes.
Recognition of Symptoms: Learn to recognize the early signs of altitude sickness. Descend to a lower elevation immediately if symptoms arise.

When to See a Doctor

Seek immediate medical attention if you experience severe symptoms such as:

Persistent shortness of breath at rest
Confusion or loss of consciousness
Chest tightness or congestion
Coughing up pink, frothy sputum (a sign of HAPE)
Severe headache unrelieved by medication

Outlook/Prognosis

With prompt treatment and proper acclimatization, most people recover fully from mountain sickness. However, ignoring the symptoms can lead to serious complications, including death. Understanding your limits, planning accordingly, and being vigilant about symptoms are key to ensuring a safe and enjoyable high-altitude experience.

Sources

Centers for Disease Control and Prevention (CDC) – Altitude Illness
Mayo Clinic – Altitude Sickness
National Health Service (NHS) – Altitude Sickness
Wilderness Medical Society – Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness
Cleveland Clinic. Altitude Sickness.
Harvard Health Publications. Altitude Sickness.
Altitude.org. Altitude Sickness.
American Academy of Family Physicians: “Altitude Illness: Risk Factors, Prevention, Presentation, and Treatment.”
BMJ. Altitude illness.
FamilyDoctor.org. High Altitude Illness: How to Avoid It and How to Treat It.”
American Heart Association. High Altitude Sickness.
American College of Emergency Physicians. Getting High: AMS, HACE, and HAPE.
Schimelpfenig, T. NOLS Wilderness First Aid, Stackpole Books, 1991.
Weiss, E. A Comprehensive Guide to Wilderness Travel, Adventure Medical Kits, 2005.
International Society of Mountain Medicine. An Altitude Tutorial.
eMedicineHealth. Altitude Sickness.