Understanding Altitude Sickness and Prevention Strategies

Altitude Sickness affects many people who travel to high elevations, especially those who ascend too quickly. It can cause discomfort and, in severe cases, pose serious health risks. Understanding what altitude sickness is, its types, causes, symptoms, and how to prevent it can help travellers enjoy high-altitude adventures safely.

Successful Summit of Island Peak at 6189m in Altitude

What Is Altitude Sickness?

Altitude Sickness, also known as acute mountain sickness (AMS), occurs when the body struggles to adjust to lower oxygen levels at high elevations. As altitude increases, the air pressure drops, and there is less oxygen available to breathe. This lack of oxygen can cause symptoms ranging from mild discomfort to life-threatening conditions.

People who ascend to altitudes above 2,500 meters are at risk. The body needs time to acclimatise and adjust to the lower Oxygen Concentration in the Air. Without a proper acclimatisation schedule, you are likely to develop altitude sickness.

Types of Altitude Sickness:

There are three main types of Altitude Sickness, each with different severity and symptoms:

1. Acute Mountain Sickness (AMS)

AMS is the most common and mildest form. Symptoms usually appear within 6 to 12 hours after reaching high altitude and include:

• Headache

• Nausea or vomiting

• Dizziness

• Fatigue

• Difficulty sleeping

• Loss of appetite

  
  

Most cases of AMS get better with additional rest and acclimatisation, but ignoring symptoms can lead to more serious conditions.

2. High Altitude Pulmonary Edema (HAPE)

HAPE is a severe condition where fluid builds up in the lungs, making breathing difficult. It can develop within 2 to 5 days after a rapid increase in altitude.

Symptoms include:

• Shortness of breath even at rest

• Persistent cough, sometimes with frothy sputum

• Chest tightness or congestion

• Weakness and decreased exercise tolerance

  
  

HAPE requires an immediate decrease in altitude and urgent medical attention.

3. High Altitude Cerebral Edema (HACE)

HACE is the most dangerous form of Altitude Sickness and causes swelling of the brain. It is usually developed as a result of undiagnosed and untreated AMS or HAPE.

Symptoms include:

• Severe headache

• Confusion or difficulty thinking clearly

• Loss of coordination or balance

• Hallucinations

• Coma in extreme cases

  
  

HACE requires an immediate decrease in altitude and urgent medical attention.

Arête à Laurence, climbing at around 3800m in Altitude

Causes of Altitude Sickness:

The primary cause of Altitude Sickness is the reduced Oxygen Level at high elevations. This leads to less Oxygen entering the bloodstream per breath, which can affect the brain and other organs. Several factors influence the risk of developing altitude sickness:

• Rate of ascent: Rapid ascending increases the risk because the body has less time to adjust to the lower Oxygen Levels.

• Altitude reached: Higher altitudes have lower Oxygen Levels.

• Physical exertion: Heavy exercise soon after arrival in an area at high altitude can worsen symptoms.

• Individual susceptibility: Some people are more prone due to genetics or health conditions.

• Previous history: Those who have had altitude sickness before are more likely to experience it again.

Symptoms to Watch For:

Recognising symptoms early is crucial to prevent progression. Common signs include:

• Headache that does not improve with painkillers

• Nausea or vomiting

• Fatigue or weakness

• Dizziness or lightheadedness

• Shortness of breath during mild activity

• Difficulty sleeping or restless sleep

  
  

If symptoms worsen or new signs like confusion, difficulty walking, or persistent cough appear, seek medical help immediately.

How to Prevent Altitude Sickness:

Preventing altitude sickness involves careful planning and gradual acclimatisation. Here are practical strategies:

Ascend Slowly

Plan your trip to increase elevation gradually. A good rule is to avoid climbing more than 300 meters per day above 2500 Meters. Include rest days every 900 meters to allow your body to adjust.

Stay Hydrated and Eat Well

Drink plenty of water to stay hydrated. Avoid alcohol and caffeine, which can cause dehydration. Eat a balanced diet rich in carbohydrates to provide energy.

Avoid Overexertion

Limit heavy physical activity during the first few days at high altitude. Take it easy and allow your body to adapt.

Use Medication When Appropriate

Some medications, like acetazolamide (Diamox), can help speed up acclimatisation. Consult a healthcare provider before your trip to discuss options.

Sleep at Lower Altitudes

If possible, sleep at a lower altitude than the highest point reached during the day. This technique, called "climb high, sleep low," helps reduce symptoms.

Recognise Early Symptoms and Act

If symptoms appear, stop ascending and rest. If symptoms worsen, descend immediately. Do not ignore warning signs.

Measuring 02 Saturation above 3000m in Altitude