I'm a doctor and I'm (relatively) young and fit, but yes I do get altitude sickness and fully expect it.
I have limited time off so I don't like "wasting" time on sea days and I love to get to places with the minimum amount of wriggle room! Unfortunately, on some occasions I have come to grief.
I'm looking at meeting the ship further down the line in Pisco or even La Serena, Chile.