Medical Alert Bracelets?

I am highly allergic to quite a few things, like bee stings, hand sanitizers, cigarette smoke, and a lot of meds(I'm on several medications for several things, but I have a lot of specifications that need to be dealt with when I'm being treated at a hospital or doctors office). Basically, whenever I have an allergic reaction my throat swells up (I've ped out before from not being able to breathe) and my aunt (who is the same way with her allergies) told me that I need to get a Medical Alert Bracelet and probably an Epi stick, but I have no idea how to go about this. I klnow that most pharmacies carry them, and that you can look thtem up on the internet and find a bunch of hits, but what do you put on them? Do you have to buy a specific type for each problem? Basically, since I can't find any really useful links, I am searching for any and all information about them that you could possibly give me. All help is greatly appreciated! Thanks!