She's been quieter this month. She's eating less. Twice last week she got confused about where the bathroom was, in the house she has lived in for thirty years. You mention it to your sister, who says gently that this is what happens. You agree. Somewhere in a drawer there's a pamphlet that told you to expect exactly this.
Six weeks later a nurse finds a urinary tract infection that had probably been there the whole time.
If the change came on over hours or days, don't start here. He's suddenly much more confused than usual covers what to check tonight and what to say when you call. Come back to this afterward.
What's actually happening
Nobody was careless. The problem is that dementia is an explanation machine. Once the diagnosis exists, every new thing has somewhere to go, and it is always the same somewhere. Quieter? Decline. Eating less? Decline. Lost in her own hallway? Decline. The story arrives instantly, costs nothing to believe, and is right often enough to keep earning your trust.
It is also the story you were prepared for. You were told to expect loss. So when loss appears, it doesn't feel like a question. It feels like confirmation.
There is a second problem underneath that one, and it's the harder of the two. Once you believe someone is declining, your memory starts agreeing with you. Ask yourself how she was three weeks ago and you won't retrieve a recording. You'll build an answer, and you'll build it out of what you currently believe. That isn't a flaw in you, it's how memory works in everyone. But it means the instrument you're using to detect the change is being quietly adjusted by the thing you're trying to detect.
The alternative: keep a record, not a vigil
The obvious response is to watch harder. That doesn't work and it doesn't last. Vigilance is expensive, you are already tired, and the thing you're watching for moves too slowly to see while you're staring at it.
What works is much smaller. Put a date next to anything new. Not a journal, not a symptom diary, not one more thing to fall behind on. Two words and a date. Nov 4, awake at 3am. Nov 11, wouldn't finish lunch. Nov 19, called me by her sister's name.
Do that for a month and you own something you cannot get any other way: a baseline that can't be revised after the fact. Then when the question comes, and it always comes, you have an answer instead of an impression.
The question is always the same one. Has this been building for a while, or did it start Tuesday? That distinction is the whole game, because dementia drifts. It arrives so gradually that no single day looks different from the one before it. The things that aren't dementia tend to break rather than drift. They arrive over hours or days, they're often worse at some times of day than others, and in your notes they show up as a line with nothing before it.
Drift is the disease. A break is a question for a doctor, today.
A few things that help
Date it, don't describe it. Two words is enough. The date is the part that matters and the part you will lose. The description is the part you'd have remembered anyway.
Write down the time of day. Half the useful patterns in dementia care are time-shaped: worse after four, worse before meals, worse on the days the aide doesn't come. You will not see that pattern by remembering. You will see it immediately once it's written down.
Keep medication changes on the same page. A new prescription, a changed dose, one that stopped. Anything that moved in the last two weeks belongs next to anything that changed in her. Usually there's no connection. When there is one, it tends to be obvious the moment the two lists sit side by side.
Ask other people before you tell them what you think. Her aide, your brother, the day program. Ask whether they've noticed anything different, then stop talking. If you lead with your theory you'll get your theory back, and you'll have spent the one independent reading you had access to.
This is Notice at its wider range. In the moment, Notice is inward and fast, catching your own reaction before it decides what happens next. Over weeks it turns outward and slow: structured attention to the person, knowing what to watch, and writing it down early enough to act on. Both are the same skill from the Steadier Ground Method, which is seeing clearly before you react. Once you can see the change, Read is what tells you where to look for the cause.
When you can't tell if something has changed
This is one piece of the full guide, "Diagnosed With Dementia: Now What?" Section 3 covers it in full, including how to track patterns over time.