They can't give personal details, but they can give non-specific ones.
You can enquire if someone is ok, and leave a message to say that you asked after their health.
( Wicca'd Witch needs ideas for a new sig on..., Mon 6 Jul 2009, 9:23, archived)

Can you ask if someone isn't OK, and leave a message saying you hope they aren't?

(rnuk http://flickr.com/rnuk, Mon 6 Jul 2009, 9:30, archived)

it's no wonder the nhs is in such a state if they allow ok people to use it

( mongychops handbrake?, that's not how i roll, Mon 6 Jul 2009, 9:33, archived)