Brain fog: putting words to it

Understanding the change · 1 September 2026 · 5 min read
A hand drawing back a sheer curtain to let in the morning light

Of all the parts of the change, this is the one that is hardest to say out loud. Warmth can be described. A broken night can be counted. But the foggy feeling arrives without a word attached to it, and in the space where the word should be, most people put something unkind about themselves instead.

It gets called all sorts of things — vagueness, absent-mindedness, "losing it", "going mad", "getting old". Almost none of those are descriptions. They are verdicts, delivered by the person experiencing it, on the person experiencing it. And a verdict is very hard to take to an appointment, because there is nothing in it a practitioner can work with.

Why it is so hard to describe

Partly because it is intermittent. It is not a constant state, it is a Tuesday. Partly because the moments it happens in are small and slightly humiliating, so they get pushed away rather than noted. And partly because the thing that would make it describable — a specific example — is exactly what the fog takes away.

"I feel stupid lately" is a judgement. "I lost the word for the thing I was holding, twice this week" is a description.

Small, concrete, at the time

The useful record here is not a rating out of ten. It is two or three real instances, written down within a few minutes of happening, before they have been smoothed over or explained away.

Any one of these on its own is entirely ordinary and happens to everyone. That is precisely why the record matters: what is worth knowing is not that it happened, but how often, and whether that has changed.

It rarely travels alone

Foggy days often sit next to something else. A run of broken nights. A stretch of warm, wakeful ones. A stressful fortnight. Seeing those side by side, in the same record, tends to change the story from "something is wrong with me" to "this week had three bad nights in it" — which is both kinder and considerably more useful. Our piece on how the threads travel together goes into that, and what is worth noticing about a night covers the sleep side.

Taking it in

Sorting out what is behind it is a practitioner's job, not yours and not an app's — there are several possibilities and they are not all the same thing. What you can bring is the material they need: how often, since roughly when, what it looks like when it happens, and what else was going on around it. That is a far better start to a short appointment than the sentence most people arrive with, and it is much harder to wave away.

Threshold is not a diagnostic tool, and not a substitute for a doctor or practitioner. It helps you notice and remember — the rest is a conversation for you and your GP or health practitioner. If something feels urgent or severe, seek medical advice promptly.

A few words, at the time.

Threshold's daily notes take seconds and keep the small specifics that would otherwise be gone by the evening — no streaks, no scores, nothing to keep up with.

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