can disclosure of menopause ...

[newtothis15]

can disclosure of menopause lead to Capability?

No. Why would you think that?

it affects work - for example, concentration etc, need more breaks

In what context would you say to an employer you were menopausal? It's not an illness or a disability.

Reasonable adjustments can and should be put in place for menopausal women- covered under the EA2010. (If symptoms are impacting)
have they made reasonable adjustments? Have you asked? There’s not enough info in your OP

It sometimes affects work for some people. But that isn't what you asked. Disclosing it (telling people you are menopausal) doesn't need doing and has no relationship to capability. Some of its impacts (what you were talking about in the quote above) may impact on capability but there is no hard and fast answer. What is reasonable in one circumstance isn't in another. Every situation is unique. For example, I have a serious disability. There are jobs that I literally couldn't do at all. There are others which I might be able to do if I have adjustments. The job that I had (until I retired) needed no adjustments because I could manage everything within the existing framework. But I couldn't say that a job in the first category must make adjustments until I can do it - that wouldn't be reasonable even if it were possible.

I think that if you're struggling at work with symptoms it would be sensible to at least consider HRT if you haven't already, and are able to use it.

if working in secondary school and i feel need more breaks between lessons...but manageent might think its unreasonable?

Well you won't know until you ask but I suspect you are correct. I doubt they will be willing or able to timetable periods between lessons for a single person. Breaks would need to match up with every other class I assume, so it would be everyone gets more/longer breaks or nobody does.

IME, unless you are particularly young, they would guess it's menopausal, and manage you out if that's what they want to do and it provides the excuse. They will avoid approaching it from a medical point and focus on performance.
Menopausal policies are tick box exercise. Can you tell I have experience of being on the receiving end of it!

Is there a reason why you won't consider HRT to help?
If this was any other condition for which there was help with a medication, would you use it?

I don't see how you can have more breaks if you're teaching/leading the class (assuming you are teaching and not a TA.)