If an aircraft calling Swanwick says it has a medical emergency, 90% will take that as read, however, there are some who will ask if you're declairing a PAN. PAN is the official word used just to make sure you're not pulling a fast one to get in first, due to both ATC and flight crew having forms to fill in. We are also trained to ask if an ambulance is required and any extras needed, we do not sort this out as a matter of course.
I do find it ironic how many aircraft wait to their first transmission with UK control, rather than declare with, in my area, the French. I except that this is purely down to that conveying the message in english to english is much easier. Thumbs up to the Speedy pilot into KK about a month ago who came in first transmission with PAN, message, and intentions, plus ambulance etc arranged, just requesting direct route. All I had to say was 'PAN acknowledged, direct 12 mile final, descend when ready FL150, no speed restriction.' and then later 'contact....' Makes it so much easier!!!