Travelling to high altitudes is an increasingly popular form of recreational holiday. Individual medical advice may be essential for certain groups of individuals such as patients with chronic disorders, pregnant women or children. This is the second part in a series of two articles on mountain medicine. The first part covered high-altitude physiology and medical aspects of objective alpine dangers and the increased exposure to ultraviolet radiation. This part covers altitude sickness, fluid balance, nutrition, and precautions for patients with pre-existing medical conditions, pregnant women and children.