"Sick" started being used as a positive term in the 1980s and 1990s, especially within skateboarding, snowboarding, and other extreme sports communities. For these athletes, landing a difficult trick or achieving something impressive often led to exclamations like "That was sick!"—emphasizing awe and respect rather than illness. It became a way to describe something that pushed the boundaries of what people thought was possible, elevating the term with a rebellious, edgy connotation.
The positive use of "sick" later spread through hip-hop culture and music, where it was used to describe impressive lyrics, beats, or performances. By the 2000s, it became common in youth culture and everyday language as a way to describe anything “awesome” or “cool,” from fashion to new technology. Today, "sick" is widely understood in its dual meaning—both literally as “ill” and as a positive slang term.