The dangers of high-altitude sickness | Explained

Prevent high-altitude sickness by acclimatising slowly, seeking medical advice, and ensuring proper healthcare infrastructure in remote areas.

The story so far: In September, a trekker from Idukki, Kerala, died in Uttarakhand while attempting to scale Garur Peak due to respiratory failure. Every year, numerous tourists like this succumb to the effects of high-altitude sickness in the pristine but challenging inner Himalayas. These regions present hidden dangers due to their extreme altitudes, where thinner air and reduced oxygen can lead to potentially fatal conditions.

High-altitude sickness, or Acute Mountain Sickness (AMS), occurs when the body cannot acclimatise to high elevations, typically over 8,000 feet (2,400 metres). As altitude increases, the air pressure and oxygen levels decrease, leading to hypoxia — a shortage of oxygen in the body’s tissues. Early symptoms of AMS include headache, nausea, fatigue, and shortness of breath. If left untreated, it can escalate into high-altitude pulmonary edema (HAPE), a life-threatening condition where fluid accumulates in the lungs, or high-altitude cerebral edema (HACE), where fluid collects in the brain. Both conditions require immediate medical intervention, and descent to lower altitudes is often the only way to prevent fatal outcomes.

At higher altitudes, the body tries to adjust by increasing the breathing rate, which can cause hyperventilation, and produce more red blood cells to carry oxygen, which thickens the blood and strains the heart. In cases of HAPE, fluid accumulation in the lungs exacerbates breathing difficulties, while HACE causes symptoms like confusion, hallucinations, and even coma.

While the Himalayan States witness a steady stream of tourists, healthcare facilities beyond major towns like Shimla are inadequate to handle cases of high-altitude sickness. Leh, in the Union Territory of Ladakh, serves as a model, having developed specialised facilities for high-altitude ailments. Yet, most high-altitude regions lack this kind of infrastructure. Immediate and preventive health measures are also lacking. Basic preventive screenings or health checks at entry points for tourists venturing into high-altitude areas could save lives. Such protocols could mirror the erstwhile “Inner Line Permit” system, whereby tourists entering high-altitude zones such as Kinnaur or Lahaul-Spiti undergo screenings at base hospitals.

To better manage high-altitude tourism, it is essential to implement a mandatory registration system for tourists entering remote mountain areas. Registrations, stored in a State government database, would allow authorities to monitor tourist movement and respond swiftly in case of emergencies. Such records would also support research on high-altitude illnesses by tracking demographic patterns and risk factors, helping scientists better understand how altitude impacts various populations.

The primary cause of high-altitude sickness is rapid ascent without allowing the body time to acclimatise. Gradual ascent, which allows the body to adapt to lower oxygen levels, is the best way to prevent high-altitude illnesses. According to the Wilderness Medical Society, travellers ascending above 3,000 meters should take a rest day every 3-4 days and avoid increasing their sleeping elevation by more than 500 metres per day.

For travellers at moderate to high risk of AMS, doctors recommend medications like Acetazolamide, which aids acclimatisation by promoting better oxygenation, or Dexamethasone, a steroid that reduces inflammation in severe cases. Those with a history of HAPE may take Nifedipine as a preventive measure, starting a day before ascent. However, no prophylactic medication guarantees complete immunity, and anyone travelling to high altitudes with pre-existing health conditions should first consult with a doctor familiar with altitude-related risks.