Doctors must identify themselves by name on Twitter if their profile alludes to their profession, new guidance has suggested.
If clinicians call themselves a doctor on social media they should also identify themselves, said the General Medical Council (GMC).
The guidance says any material written by authors who call themselves doctors is "likely to be taken on trust", and tweets posted by clinicians should maintain public trust in doctors.
"The standards expected of doctors do not change because they are communicating through social media rather than face-to-face or through other traditional media," the GMC professional standards say.
"If you identify yourself as a doctor in publicly accessible social media, you should also identify yourself by name. Any material written by authors who represent themselves as doctors is likely to be taken on trust and may reasonably be taken to represent the views of the profession more widely."
One medic questioned whether the move would lead to "the end of anonymity".
Consultant physician Phil Berry posted on the micro blogging site: "If you identify yourself as a Dr you..should identify yourself by name' < the end of anonymity?"
The guidance forms part of the GMC's professional standards for doctors.
Dr Catherine Wills, adviser at the Medical Defence Union, said: "Social media can be a force for good in medicine, for example, by helping doctors to network more effectively and giving patients access to more healthcare information.
"But there are risks too, particularly when it comes to maintaining boundaries with patients and acting professionally and we are pleased that the GMC's guidance has addressed such a growing issue for our members."