Lynne Spalding, of San Francisco, was last seen by hospital personnel at about 10:15 a.m. last Saturday while she was being treated for an infection, according to David Perry, a spokesman for her family.
Hospital employees who had been checking on her every 15 minutes went back to her room at 10:30 a.m., found she was no longer there and notified police, Perry said.
A missing persons report was filed with police, who are investigating her disappearance, Perry said.
Spalding has lived in San Francisco for several years and was in between jobs after having worked in hospitality sales, Perry said.
She is described as Caucasian, 5 feet 7 inches tall, weighing 105 pounds and believed to have been wearing blue jeans, black boots and a black sweatshirt with the words "San Francisco Pow Wow" embroidered on it, according to Perry.
Spalding, a native of Great Britain, speaks with a very heavy British accent, Perry said.
Her family members and friends are concerned because she is very thin and frail, was on medication and very confused when she was last seen, Perry said.
Anyone who might have seen Spalding is urged to notify San Francisco police at (415) 553-0123. Pictures of her have been posted on a Facebook page set up for her that may be found by searching for FINDLYNNE on Facebook.