You feel it in your chest before you can name it. You're in what looks, from the outside, like a healthy relationship. Your partner is kind. They show up. There's no obvious reason to feel this unsettled. And yet you spend hours replaying conversations, scanning for signs that something is wrong, wondering if what you're feeling means something important.

It starts somewhere around late afternoon. A low-grade tightening that doesn't have a specific cause, or has too many at once to identify. By evening, you're not quite present for whatever you're doing. Monday is not here yet, and already it is.

Sunday night anxiety, sometimes called the Sunday scaries, is common enough to have a name. It is also common enough to be dismissed as a personality quirk, or as something that is simply part of having a demanding job or a full life. But what it usually is, when it shows up consistently, is the body's anticipatory stress response running ahead of the week, and that consistency is worth paying attention to.

You meet every deadline. You respond to messages promptly. You have already thought through three contingencies for the thing that hasn't happened yet. From the outside, you look like someone who has it together. From the inside, it is exhausting.

"High-functioning anxiety" is not a clinical diagnosis. It is a term that describes a particular pattern of lived experience…