Half the joy of basing yourself in the Kullu Valley is how easily you can climb from apple orchards to snow in a single morning — Rohtang, Chandratal, Hampta Pass and the Lahaul–Spiti roads all sit well above 4,000 m. That fast gain in height is also why every hill traveller should understand acute mountain sickness (AMS) before heading up.
What altitude sickness is
As you climb, the air holds less oxygen. Above roughly 2,500 to 3,000 m the body has to work harder to cope, and if you ascend faster than it can adjust, AMS can set in. It has little to do with fitness — strong, young trekkers get it as often as anyone. Chandratal at about 4,300 m and the high Manali–Leh passes are the usual trouble spots for Kullu-based travellers.
Know the symptoms
Mild AMS usually appears 6 to 24 hours after gaining height and feels like a bad hangover: headache, nausea, tiredness, loss of appetite and disturbed sleep. These are warning signs, not something to push through. The dangerous forms — fluid on the lungs (HAPE) or the brain (HACE) — are rarer but serious, marked by breathlessness at rest, a persistent cough, confusion or an unsteady walk. Any of these means descend at once and get help.
How to prevent it
- Ascend gradually. Above 3,000 m, try not to raise your sleeping altitude by more than about 300 to 500 m a day, and build in a rest day every few days.
- Acclimatise low first. Spending a night or two at a moderate height before going high makes a real difference.
- Hydrate. Drink plenty of water through the day; the dry mountain air dehydrates you quickly.
- Go easy at first. Avoid alcohol, cigarettes and hard exertion for the first 24 hours up high.
- Consider Diamox. Acetazolamide can help prevent AMS, but only take it after speaking to a doctor.
- Climb high, sleep low. It's fine to visit a high point by day as long as you come down to sleep.
Why Naggar helps
Naggar sits at around 1,800 m — high enough to begin gently priming your body, low enough to be completely comfortable. Spending a night or two here before you drive up to Rohtang or across to Lahaul lets you rest after the journey from the plains and start acclimatising without even trying. Ghar in the Hills is a cosy homestay in Naggar village that makes an easy first stop — good sleep, home-cooked food and valley air before you head for the heights.
The golden rule
If you feel unwell as you climb, stop going up. Rest at the same height until you're better, and if symptoms get worse, go down — descent is the one thing that reliably cures altitude sickness. No view is worth gambling your health for, and the mountains will still be there next season.
Plan your high-altitude days with a little patience and AMS rarely becomes a problem. Base yourself low, climb slowly, listen to your body — and book a night in Naggar to start your trip on the right foot.