When does poor concentration become ADD? Does it matter?

[TeenDivided]

After another session where it was hard to get DD to try/focus for 20mins of maths, I was looking at www.nhs.uk/conditions/attention-deficit-hyperactivity-disorder-adhd/symptoms/ and my 17yo meets most of the items on the 'signs for inattentiveness'. On the related conditions list she has anxiety, depression, dyspraxia and dyslexia. She also has limited 'delayed gratification' ability to work at longer term things. But she can focus if doing something that interests her.

And does it matter / make any difference whether this is 'just' poor concentration or is ADD?

Hello, just wanted to post as my 14 year old son has just been diagnosed with ADHD (inattentive type, so not hyperactive).
For years I thought the problems concentrating on school work were caused by his dyslexia. He's always need a lot of support getting organised and is quite often so exhausted after school that he goes to bed. Y9 has been really difficult, he's not making progress academically so that was the trigger for the ADHD assessment. We paid privately due the waiting list and it seemed the council diagnosis process was geared towards the hyperactivity type and not inattentive. He's going to try medication over the summer. I just wanted to post our experience so far in case it's helpful