Police said David Jones, 54, was last seen leaving Royal Preston Hospital in the early hours of Wednesday morning after suffering a fall at his home.
But David failed to return home and he has not been seen or heard from since, according to police.
David is described as white, of slim build, with short grey hair and a white beard.
A police spokesman said: "We are becoming increasingly concerned about the welfare of 54-year-old, David Jones, who is missing from their home address in Preston.
"He was last seen leaving Royal Preston Hospital in the early hours of Wednesday, January 29.
"We are now concerned for his welfare and are appealing for your help to find David.
"If you have seen him or have any information, please call us on 101 quoting log reference LC-20200129-0651."