Themes of acceptance run throughout the show, with frank discussions about how our differences make us stronger.
As the show is a medical drama, you can expect to see the usual amount of operating room scenes -- bodies open on the table, innards exposed during surgery -- and sometimes the accidents that lead up to someone being hospitalized. There are some flashbacks of the young Shaun being physically bullied by peers. An animal is thrown against a wall in one scene (we don't see the immediate aftermath). Some security guards tackle a character roughly.
Typical hospital romance stuff: residents under the covers together in the on-call room, a kiss in a hallway. References to "screwing."