Altitude sickness: a traveller's guide to Ladakh and the high Himalaya

Acute mountain sickness (AMS) is the body's reaction to gaining altitude faster than it can adjust, and it is a genuine risk anywhere in the higher reaches of Ladakh, Kashmir's highlands or a Himalayan trek, not just on technical climbs. Mild AMS is common and usually manageable — a headache, nausea, dizziness, poor appetite or disturbed sleep — but it can, if ignored, progress to more serious and occasionally life-threatening conditions affecting the lungs or brain. The good news is that AMS is largely preventable with a sensible ascent plan, and the itinerary itself is the main safety measure.

Leh, the base for almost every Ladakh trip, sits at about 3,500 metres, and the region's famous sights — Khardung La, Pangong Tso, the high passes — go higher still. Flying directly into Leh takes you from near sea level to that altitude in a couple of hours, which is exactly the kind of rapid ascent that raises AMS risk, so a full rest day on arrival is non-negotiable regardless of how you got there.

A road approach, via the Srinagar-Kargil-Leh or Manali-Leh highways, gains height more gradually over several days, which can help acclimatisation — but only if the drive itself is not rushed. Racing over the high passes in a day or two removes that advantage and can be just as risky as flying in without a rest day, since you still reach altitude quickly relative to how long your body needs to adjust. Either way, the plan matters more than the method of arrival.

• Build in a full rest day on arrival at altitude before ascending any further, and ascend gradually after that rather than in large jumps.
• Drink far more water than feels natural, since dehydration makes altitude symptoms worse.
• Avoid alcohol for the first 24 to 48 hours at a new altitude, and go easy on it after that.
• Know the warning signs of worsening AMS, including a headache that will not resolve, persistent vomiting, breathlessness at rest, confusion or difficulty walking in a straight line — these mean you should descend rather than push on.
• Medication exists that some travellers use to help prevent or ease AMS, but this is a decision to make with your own doctor before you travel, not something to decide on the road.

• Do build a rest day into your itinerary immediately on arrival at altitude, wherever you fly or drive in.
• Do ascend gradually after that, sleeping at progressively higher altitudes rather than jumping straight to the highest point on your route.
• Do drink substantially more water than you would at sea level.
• Do tell your guide or driver immediately if you feel unwell — altitude symptoms are far easier to manage early.
• Don't drink alcohol in your first 24 to 48 hours at a new altitude.
• Don't exert yourself heavily — a long trek, a fast climb, strenuous exercise — on your first day or two at altitude.
• Don't ignore a worsening headache, breathlessness at rest or confusion; these are signs to descend, not push through.
• Don't decide on altitude medication yourself; discuss it with your doctor before you travel.