Ladakh Without Altitude Sickness: The Acclimatisation Plan That Works

Why Leh catches people out

Leh sits at 3,500 metres. The flight from Delhi takes 80 minutes. You step off an aircraft pressurised to the equivalent of about 2,400 m into air with roughly 65% of the oxygen you had at breakfast, and your body has had no opportunity to do anything about it. Almost nowhere else in India lets you gain that much altitude that fast.

The trekkers driving up the Manali–Leh highway over four days rarely have a problem. The fly-in tourists do, and they are the majority. Studies at Leh have consistently found acute mountain sickness in roughly a quarter to a third of arrivals by air, against a small fraction of those arriving overland.

Fitness offers no protection at all. Marathon runners get AMS. Twenty-five-year-olds get it more often than sixty-year-olds, largely because they refuse to rest on day one. The only reliable variables are how fast you ascended and how high you sleep.

What AMS actually feels like

Acute mountain sickness is not a dramatic illness at first. It presents as a headache plus at least one other symptom, and most people initially blame the flight, the food or a bad night's sleep. The diagnostic rule of thumb used in mountain medicine is blunt: if you have a headache at altitude, assume it is AMS until proven otherwise.

• Headache, usually frontal, worse in the morning and worse when you bend over.
• Nausea or loss of appetite. Wanting to skip dinner on your first night in Leh is a signal, not a preference.
• Fatigue out of proportion to what you have done. Being exhausted by a flight of stairs.
• Dizziness or light-headedness on standing.
• Broken sleep, and periodic breathing at night — a cycle of fast breaths then a pause, which frightens the person sharing the room more than the person doing it.
• Breathlessness on mild exertion. Normal at 3,500 m. Breathlessness while sitting still is not, and it is a different problem.

The 500 metre rule

Above 3,000 m, do not increase your sleeping altitude by more than about 500 m per night, and take a full rest day every 1,000 m of gain. What matters is where you sleep, not the highest point you touched during the day. Driving to Khardung La at 5,359 m and coming back down to Leh to sleep is fine. Driving to Khardung La and continuing to sleep at Nubra on your second day in Ladakh is not.

Climb high, sleep low is the entire principle in four words, and Ladakh's geography suits it well. Day trips out of Leh to Khardung La, Shanti Stupa and the Indus valley monasteries let you touch high altitude and recover overnight at 3,500 m.

The itineraries that produce problems are the ones that gain sleeping altitude on consecutive nights: Leh at 3,500 m, then Nubra at 3,050 m, then straight over Shyok to Pangong at 4,250 m. That last leg is a 1,200 m jump on to a lake where the nearest hospital is five hours away over a 5,300 m pass.

Two nights in Leh before you go anywhere

This is the single most important line in any Ladakh itinerary, and it is the one operators cut first when a client wants a shorter trip. Land in Leh, go to your hotel, and do nothing for the rest of the day. Not a light walk around the market. Nothing. Lie down, drink water, eat something plain.

Day two is a gentle Leh day: Shanti Stupa, the palace, Thiksey and Hemis monasteries, all under 3,700 m, all reached by car with short walks. You are testing whether your body has adapted while staying within reach of Leh's hospital.

You leave for Nubra or Pangong on day three at the earliest. A seven-day Ladakh itinerary that begins the Nubra drive on day two is not saving you a day, it is spending your holiday on Diamox and a headache. If someone is selling you a five-day fly-in Ladakh trip covering Nubra and Pangong, they are selling you a medical risk.

The oxygen concentrators that most Leh hotels now keep at reception, and the oxygen cylinders in the Pangong camps, exist because this rule gets broken constantly.

The Diamox conversation

Acetazolamide, sold as Diamox, works. It acidifies the blood slightly, which drives up your breathing rate and speeds the adaptation your body would make anyway over several days. The usual prophylactic dose is 125 mg twice daily, started the day before ascent and continued for two days at altitude, but this is a prescription drug and the dose is a conversation with your doctor, not with a travel blog.

It is not a permit to skip acclimatisation. Diamox reduces the incidence of AMS; it does not prevent high-altitude pulmonary or cerebral oedema, and it will not save an itinerary that gains 1,200 m in a day. Treat it as insurance on a sensible plan, not as a substitute for one.

Side effects are real and mildly unpleasant: tingling in the fingers and lips, a strong diuretic effect that has you awake twice a night, and carbonated drinks tasting flat. It contains a sulfonamide group, so anyone with a sulfa allergy should not take it. Talk to your physician four weeks before you travel, not at the airport.

Red flags: when to descend immediately

Ordinary AMS is managed by stopping where you are, resting, hydrating and taking paracetamol. If you are not better after 24 hours, or you are worse, you go down. Descent of 500 to 1,000 m fixes almost everything, and it fixes it fast.

Two conditions are different and they are emergencies. High-altitude cerebral oedema shows as confusion, unusual behaviour, a severe headache that does not respond to painkillers, and — the classic test — an inability to walk heel-to-toe in a straight line. High-altitude pulmonary oedema shows as breathlessness at rest, a persistent dry cough that turns wet or frothy, extreme fatigue and a blue tinge to the lips.

• Cannot walk a straight line heel-to-toe — descend now, do not wait for morning.
• Confusion, drowsiness or behaviour that is out of character.
• Breathlessness while sitting still, or a cough producing frothy sputum.
• Headache that does not improve with paracetamol and rest.
• Vomiting that stops you keeping fluids down.
• Blue or grey lips and fingertips.

A fly-in itinerary that respects the altitude

The seven-night shape that works: two nights Leh doing almost nothing, one night Nubra at 3,050 m via Khardung La, one more night Nubra, two nights Pangong or one night Pangong and one back in Leh, then the flight out. Note that Nubra is actually lower than Leh, which makes it the correct second stop, and that Pangong at 4,250 m comes only after five nights of adaptation.

Drink 3 to 4 litres of water a day, more than feels reasonable. Skip alcohol entirely for the first 48 hours; a beer at 3,500 m on your first night does roughly what three would at sea level and it suppresses the breathing drive you need. Eat carbohydrate-heavy food even without appetite.

Carry paracetamol, an oral rehydration salt, and a small fingertip pulse oximeter, which costs under USD 20 and gives you an objective number. Readings of 80–88% are normal for an acclimatising visitor in Leh. Below 75% with symptoms, and you are talking to a doctor at SNM Hospital, not waiting to see how the night goes.