The head of Y Combinator once worked so hard he gave himself scurvy

The summer after he dropped out of Stanford, Sam Altman worked himself so hard he developed an 18th century disease.

The head of Y Combinator is the subject of a new profile from The New Yorker. In it, author Tad Friend describes Altman’s rise from a Stanford dropout to becoming a powerful force in the Silicon Valley startup world, including the summer he began working on his own startup.

Altman and two of his classmates founded Loopt, an app that let users find out their friends’ locations. The company became a member of the first class of Y Combinator and began working nonstop. So nonstop, in fact, that Altman developed scurvy.

According to the U.S. National Library of Medicine, scurvy occurs when someone has a severe lack of Vitamin C in their diet, causing weakness, anemia, gum disease, and skin hemorrhages. And it’s pretty rare: There are fewer than 20,000 cases of it each year in the US.

Altman appears to have recovered just fine, since Friend’s profile also mentions he often completes 100-mile bike rides and can do an impressive number of pull-ups. But the profile is a revealing look at one of the Valley’s more fascinating characters, so it’s worth heading over to The New Yorker to read the full piece.