A mania is an intense, excessive enthusiasm or obsession with something. When someone has a mania for collecting baseball cards, they think about it constantly, spend all their allowance on it, and can barely talk about anything else. A mania for video games might mean playing for hours every day, ignoring homework and friends.

The word suggests something beyond normal interest or hobby. Lots of kids enjoy soccer, but a mania for soccer would mean someone who watches every game, memorizes every statistic, practices until dark every single day, and gets genuinely upset if they miss even one practice.

In medicine, mania describes a serious mental state where someone feels extremely energetic, talks rapidly, sleeps very little, and makes impulsive decisions. Someone experiencing clinical mania might suddenly decide to reorganize their entire house at 3 a.m. or start five new projects at once without finishing any of them.

Mania can also describe crazes that sweep through groups of people. Beatlemania described the wild excitement when the Beatles became famous in the 1960s. When people line up for hours to buy the newest phone or toy, that's a kind of mania too: a temporary frenzy where good judgment takes a back seat to overwhelming enthusiasm.