Altitude Sickness (Acute Mountain Sickness)

Altitude sickness, also known as Acute Mou

ntain Sickness (AMS), is a health condition that affects people who ascend to high altitudes too quickly, especially without proper acclimatization. It is caused mainly by the lower levels of oxygen available at high elevations. The air becomes thinner as elevation increases, and this makes it harder for the body to take in enough oxygen to function properly. AMS is common among hikers, trekkers, and travelers who go to mountainous regions wi

thout giving their bodies time to adju

st.

Introduction

• Altitude sickness is a physical reaction of the body to reduced air pressure and lower oxygen levels at high elevations. It is most commonly observed in individuals who travel to elevations above 2,500 meters (8,200 feet) rapidly.
• At higher altitudes, the atmosphere contains less oxygen. A person at sea level breathes air that contains about 21% oxygen. At 3,000 meters, the oxygen level drops significantly, making breathing more difficult and affecting how the body functions.
• It can affect anyone, regardless of age, gender, or fitness level. However, people with pre-existing lung or heart problems are at greater risk.

Probable Elevation for Altitude Sickness

• Below 2,500 meters (8,200 feet):
  • Generally safe for most people. Symptoms of altitude sickness are rare unless there is a very rapid gain in altitude without any acclimatization.
• 2,500 to 3,500 meters (8,200 to 11,500 feet):
  • Mild symptoms of AMS may appear. This is the elevation where most cases of AMS begin to develop.
• 3,500 to 5,500 meters (11,500 to 18,000 feet):
  • The risk of AMS increases greatly. Proper acclimatization and gradual ascent are strongly recommended. Many popular trekking destinations like Everest Base Camp, Annapurna Base Camp, and Mount Kilimanjaro fall within this range.
• Above 5,500 meters (18,000 feet):
  • This is considered extreme altitude. Almost everyone experiences some degree of altitude sickness here. Oxygen levels are significantly lower and serious medical complications like High Altitude Pulmonary Edema (HAPE) or High Altitude Cerebral Edema (HACE) can occur.

Who is Likely to Suffer From Altitude Sickness:

• First-time travelers to high altitude:
  • Those who have never been exposed to high elevation are more likely to develop AMS because their body has not experienced such oxygen-deficient conditions before.
• People with fast ascent:
  • Ascending rapidly without giving the body time to adjust increases the chances of altitude sickness. Traveling from sea level to high altitude by flight or vehicle without stops is risky.
• People with respiratory or cardiovascular problems:
  • Individuals who already have issues with breathing or blood circulation are more vulnerable because their bodies are less capable of handling lower oxygen levels.
• Young and middle-aged adults:
  • Interestingly, some studies show that young and fit individuals may be more prone because they tend to push themselves harder and ascend faster, unlike older travelers who may move more cautiously.
• People who have experienced AMS in the past:
  • If a person has suffered from altitude sickness before, they are more likely to experience it again in future high-altitude journeys.

 Symptoms of Altitude Sickness:

Altitude sickness symptoms can range from mild to life-threatening. They usually appear within 6 to 24 hours after reaching a higher elevation.

• Mild to Moderate Symptoms:
  • Headache: This is usually the first and most common symptom.
  • Nausea and Vomiting: Feeling sick or actually vomiting due to reduced oxygen supply to the stomach.
  • Dizziness and Lightheadedness: Caused by the brain receiving less oxygen.
  • Fatigue and Weakness: The body tires more easily with even minimal exertion.
  • Loss of Appetite: The digestive system slows down at higher altitudes.
  • Disturbed Sleep: Insomnia or frequent waking is common.
  • Shortness of Breath: Especially when walking or climbing.
• Severe Symptoms:
  • HAPE (High Altitude Pulmonary Edema): Accumulation of fluid in the lungs, leading to breathlessness, chest tightness, and cough with frothy sputum.
  • HACE (High Altitude Cerebral Edema): Swelling of the brain, causing confusion, difficulty walking, slurred speech, and possible unconsciousness.

These severe forms are medical emergencies and require immediate descent and medical care.

 Prevention of Altitude Sickness:

• Gradual Ascent:
  • Increase altitude slowly. Ascend no more than 300 to 500 meters per day once above 2,500 meters. Take a rest day every 3 to 4 days.
• Stay Hydrated:
  • Drink plenty of water. Dehydration can worsen AMS symptoms. Avoid alcohol and caffeine as they can lead to dehydration.
• Proper Acclimatization:
  • “Climb high, sleep low” is a golden rule. Go higher during the day but return to a lower altitude to sleep.
• Medication:
  • Acetazolamide (Diamox): Helps the body adjust faster by stimulating breathing. Should be taken after medical consultation.
  • Dexamethasone: A steroid used to reduce brain swelling in severe AMS.
• Avoid Overexertion:
  • Do not push your body too hard when you are not yet acclimatized. Walk slowly, take breaks, and listen to your body.
• Know the Symptoms:
  • Be aware of the early signs of AMS. Stop climbing if symptoms develop and never ascend higher if they worsen.
• Oxygen Support:
  • In very high altitudes, portable oxygen cylinders or bottled oxygen can be helpful, especially for those at risk.
• Buddy System:
  • Always travel with a companion. They can recognize symptoms in you that you may miss in yourself. As you will be accompanied by your guide and team, there is no need to worry about.

Altitude sickness is a serious yet preventable condition. With awareness, preparation, and a slow and steady approach to high-altitude travel, most people can enjoy their journey without health problems. Understanding the causes, symptoms, and preventive methods is crucial for all adventurers heading to mountainous regions, particularly in countries like Nepal, where popular trekking routes often reach elevations above 3,000 meters. Always respect the altitude and let your body adjust at its own pace.