There have been no confirmed sightings of Cathryn Holdsworth for more than a fortnight.
The 72-year-old was seen at Calderdale Royal Hospital on Friday, September 8.
It was captured on cameras at the Tesco store in Halifax town centre at around 5.20pm on Saturday, September 9.
Inspector Toby Facey, of Calderdale Police, said: “It has now been over two weeks since Cathryn was last seen and we are growing more and more for Cathryn’s welfare. She has not be seen for around 10 days, which is very out of character.
“Cathryn lives with a number of health issues which make her more vulnerable and we are appealing to anyone who can assist us in locating her to come forward so we can make sure she is OK."
Ms Holdsworth was reported missing by neighbours in the Holdsworth Road area of Illingworth on Tuesday, September 19.
She was using her walking frame and wearing distinctive pink earmuffs, a dark coloured coat and pink gloves when last seen.
She is around 5ft 2in and of medium build, with very short, speckled grey hair and dark glasses.
It is believed that Ms Holdsworth may have some family in Cornwall, but she also has previous links to Blackpool in Lancashire.
Police say she may also have contacts across Calderdale, West Yorkshire and the UK.
Insp Facey said: “Anyone who has seen or heard from Cathryn should speak to police.
"I would also appeal directly to Cathryn to contact police to let us know that she is OK.”
Anyone who has seen or heard from Cathryn since September 8, or who knows where she is now, is urged to call West Yorkshire Police via 101 and quote 1520 of 19/09.