Well, it’s really a Scottish phrase isn’t it and it’s what people say when they are feeling discombobulated and troubled about something or someone is ‘getting at them’.
For some reason the phrase is often used by husbands, about their wives of course.
She’s nippin’ ma heid or in English-She’s hurting my head. It means that someone or something is giving you grief, causing you severe annoyance.
It doesn’t always have to be a person that’s causing the problem. It can be a large company like British Gas or BT. The sort of company that keeps you on hold for ages when you phone them and you can never speak to an actual human being. It does your head in, it really annoys you, but I think that there’s no point in letting yourself be bothered like that. Rise above it otherwise the only thing that does go up is your blood pressure!