How many acclimatization days do I really need?

Minimum 2 acclimatization days (Namche and Dingboche), but 3-4 is safer if you've never been above 4,000m. Better to over-acclimatize than risk altitude sickness.

Can I skip acclimatization days if I feel fine?

No. Altitude sickness can hit suddenly even if you feel great. The 'climb high, sleep low' principle is non-negotiable above 3,000m.

What if I get altitude sickness on an acclimatization day?

Descend immediately if you have severe symptoms. Mild headaches are normal, but vomiting, confusion, or difficulty walking means go down at least 500m and rest.

Should I take Diamox during acclimatization days?

Consult your doctor, but many trekkers take 125mg twice daily starting 2 days before gaining altitude. Don't rely on it alone - proper acclimatization days are still essential.

How to Plan Everest Base Camp Trek Acclimatization Days

Plan 3-4 acclimatization days during your EBC trek: one in Namche Bazaar (3,440m), one in Dingboche (4,410m), and optionally one in Lobuche (4,940m). Each acclimatization day should include a higher altitude day hike followed by sleeping at the lower base altitude.

Map your altitude profile. Chart your daily sleeping altitudes from Lukla (2,800m) to Base Camp (5,364m). Identify jumps over 500m in sleeping altitude - these need acclimatization days before or after.
Schedule Namche Bazaar rest day. Plan your first acclimatization day in Namche Bazaar after 2 nights there. Hike to Everest View Hotel (3,880m) or Khumjung village (3,790m) in the morning, return to sleep at 3,440m.
Add Dingboche acclimatization day. After reaching Dingboche (4,410m), plan a full rest day. Hike to Nagarjun Hill (5,100m) or Chhukung Ri (5,546m) depending on your fitness level. Return to sleep at 4,410m.
Consider Lobuche rest day. If you're feeling altitude effects or want extra insurance, add a half-day in Lobuche (4,940m). Short hike toward Kala Patthar viewpoint (5,643m) without reaching the summit.
Build buffer days into your itinerary. Book 16-18 days total including acclimatization days and 2 buffer days for weather delays. Don't count on perfect conditions or feeling great every day.

How many acclimatization days do I really need?: Minimum 2 acclimatization days (Namche and Dingboche), but 3-4 is safer if you've never been above 4,000m. Better to over-acclimatize than risk altitude sickness.
Can I skip acclimatization days if I feel fine?: No. Altitude sickness can hit suddenly even if you feel great. The 'climb high, sleep low' principle is non-negotiable above 3,000m.
What if I get altitude sickness on an acclimatization day?: Descend immediately if you have severe symptoms. Mild headaches are normal, but vomiting, confusion, or difficulty walking means go down at least 500m and rest.
Should I take Diamox during acclimatization days?: Consult your doctor, but many trekkers take 125mg twice daily starting 2 days before gaining altitude. Don't rely on it alone - proper acclimatization days are still essential.