A British surgeon has saved his long-lost friend's life by diagnosing his burst appendix online, thanks to popular social networking site 'Facebook', a media report said.

Rahul Velineni, 30, logged on mid-shift and saw posts from his former schoolmate telling friends that his stomach was in agony. The medic did not have his phone number because they had lost touch -- so messaged him from Swansea Hospital: "Sounds bad, Call me asap. You may have appendicitis," The Sun reported.