I have suffered the same issue. Even when checking that server and game versions are not mismatched the issue prevails. Logging into another server can rectify the issue but on some occasions rejoining the server after a short period does work. However this does seem to be a big in client/server communication.

To regen lost blood, eat and drink until your status is "healing" this will replace blood loss.

If you get sick you need to find a hospital/medical center where you can pick up antibiotics or charcoal tablets.

check out reddit/r/dayz for people to play with.

what you report is not a bug but a game mechanic

No other doors were opening

Just to point out for you folks, DayZ is a 32bit game therefore can only see and use 4GB of Ram. Memory is not part of the issue