Why Leh feels different
Leh is roughly 3,500 metres above sea level. Oxygen availability is lower from arrival. Fitness, youth and previous trekking do not guarantee protection from altitude illness.
The first 48 hours
Fly-in travellers should keep arrival day for complete rest and the following day for gentle Leh or Indus Valley sightseeing. Avoid alcohol, strenuous exercise and higher sleeping points while acclimatising.
Common symptoms
Headache, nausea, dizziness, appetite loss, unusual fatigue and disturbed sleep can occur. Stop ascending when symptoms develop and tell companions rather than hiding discomfort.
Emergency warning signs
Breathlessness at rest, confusion, inability to walk straight, severe weakness or worsening cough require urgent medical assessment and descent. Oxygen can support an emergency response but is not permission to remain high.
Medication disclaimer
Acetazolamide, commonly known as Diamox, is sometimes prescribed but has contraindications and side effects. Discuss it with a qualified clinician who knows your history; do not self-prescribe from online advice.
Roads, government procedures, mobile arrangements, prices and weather change. Reconfirm close to departure through official authorities and your registered local operator.