Starting new job

I was wondering how people would approach discussing there Asthma when starting a new job. As most of you know Tesco has caused me a lot of hassle and i am now happy to be away and i am really looking forward to starting my new job however I am worried how my asthma will be viewed and if it will be a problem et and don't know how to approach telling people about it etc or if i maybe shouldn't. what would people reccomnd?