Hiccups are a manifestation of 'constriction release' - when you are for instance in a certain specific application, so 'focused' and 'consumed' by the application, that you 'forget' about you as the application as the expression of you.
So, for instance, let's say you focus so much on your breathing, instead of realising: That I am here as the breath - and you 'separate you from the breath', your entire human physical body as you within you - 'compresses together tightly in inside you' and then the hiccups come - to release the 'tightness' inside you - to allow you to flow as the breath as you here.
So, the human physical body uses hiccups to release the 'tightness' of you within and as the human physical body - to allow you to realise: I am here, the hiccups 'bring you back here' as awareness of you within and as your human physical body.
Realise when you breath, that you are the breath - don't 'put all your attention on the breath only' - realise that it is you as who you are within you as the breath - it's not about the breath, it's about you as the breath. Then you flow - and don't constrict yourself within you.