Adhd is not usually diagnosed for one of these symptoms. But if you have a lot of them there's a pattern of likelihood that you have it.
I'm diagnosed and one of my biggest issues with adhd is this reading issue for me. Which also gets compounded with my less than half of the usual short term memory length of around 8 and a half seconds.
Ok so what I’m about to say is my own experience can’t speak for anyone else but IMO with my ADHD it’s basically a normal brain with some attributes for better or for worse are enhanced
Like yeah everyone loses focus sometimes, everyone sometimes just stops processing language, everyone gets distracted by something, everyone gets excited about a topic they like, and so on
But as one of my favorite posts said: “everyone pees, but when you pee 60 times a day you should probably see a doctor”