LadySybil
Thanks Gagajo, just saw your post after writing my last one. It is potentially very dangerous, there should be someone as well as PALS this could be taken to surely.
Your first step should be to contact the hospital and ask them to look up everybody who has accessed your records, which shouldn't be too difficult.
If you have proof that somebody has accessed your records without authorisation, you should contact the Information Commissioner's Office, who investigate breaches of data protection. If you are intending to take legal action, it would be a good idea to get a solicitor.