The average altitude in Gilgit-Baltistan is 11,000 feet (3,350 meters), and most multi-day hikes will take you higher than this. If you’ll be hiking above 13,123 feet (4,000 meters), make sure to check your travel insurance covers altitude travel. The highest campsite on my Nangma Valley hike sat at 12,959 feet (3,950 meters), with an optional side-trek to Amin Brakk Base Camp (14,764 feet/4,500 meters).
K2 Base Camp sits at 16,732 feet (5,100m), about 1,181 feet (360 meters) lower than Nepal’s Mount Everest Base Camp. With the first symptoms of altitude sickness typically experienced at 10,000 feet (3,000 meters), I took Diamox (a prescription drug that accelerates acclimatization) as a preventative measure. But medication, as always, is a conversation for your doctor.