Twitter content is user-generated
Medics posting messages on networking websites like Facebook and Twitter are breaching patient confidentiality, a leading journal reveals.
Research in the Journal of the American Medical Association found examples of web gossip by trainee doctors sharing private patient stories and details.
Over half of 78 US medical schools studied had reported cases of students posting unprofessional content online.
One in 10 of these contained frank violations of patient confidentiality.
Most were blogs, including one on Facebook, containing enough clinical detail that patients could potentially be identified.
Many postings included profanity and discriminatory language.
Sexually suggestive material and photos showing drunkenness or illicit drug use were also commonplace.
While most incidents resulted in informal warnings, some were deemed serious enough to lead to dismissal from medical school.
But few of the medical schools had policies that covered online social networking and blogging.
The investigators, led by Dr Katherine Chretien of the Washington DC VA Medical Center, said medical students may not be aware of how online posting can reflect negatively on medical professionalism or jeopardise their careers.
Similarly, patient confidentiality breaches may be unintentional.
"Sharing patient stories that are de-identified and respectful, as health professionals might do on personal blogs, can encourage reflection, empathy and understanding.
"However, content may risk violation of patient privacy, even without using names or other identifiers," they warned.
Also, the line separating freedom of speech and inappropriate postings can be unclear - for example, derisive comments about a student's institution or profession might not be considered unprofessional by some, they said.
Dr Chretien's team say medical students should be taught as part of their training about the risks associated with making postings on the Internet.
As a matter of course, students should be shown how to elect privacy settings on social networking sites and should be told to perform periodic Web searches of their own name to vet listed online content.
A spokesman for the British Medical Association said: "Patient confidentiality is paramount and medical students and doctors obviously need to be very careful about any information they post online."
The UK's regulator of doctors, the General Medical Council, does not have guidance that covers medics' blogging.
But a spokeswoman advised doctors: "You must make sure that your conduct at all times justifies your patients' trust in you and the public's trust in the profession."