I saw a great statement by Walter Williams, not sure if he's the one who came up with it. It's a good litmus test for what's NOT a right.

Something can't be a right if it implies an obligation on someone else.

Not sure if I quoted it exactly, but if not it's pretty close. This is, in my opinion, a very good point of view. Using this it's obvious that healthcare is not a right as some people can't afford it and thus would require others (the obligation) to pay for it.