The son of a missing man who suffers from Parkinson's disease said life has felt like a "bad dream" ever since his father's disappearance.
The family of Arthur Prosser hope for good news about the 67-year-old before Christmas Eve when it will be three weeks since his disappearance.
Mr Prosser went missing from the Narborough Road area of Leicester at around 10.30am on December 3 and has not been seen since.
He suffers from Parkinson's disease, does not have any medication with him and failed to pick up his prescription from a pharmacy in Leicester, police said.
His son Graham said the last few weeks without his father had been a nightmare.
"It's been three weeks now and I just want him home," he said. "I still feel I'm in a bad dream and that I'm going to wake up and dad will be back home.
"I want to make a personal appeal to anyone out there who knows anything about my dad's disappearance or for my dad himself to contact me or the police to let us know he is safe and well."
Mr Prosser is described as white, approximately 5ft 9in, with grey receding hair which has some dark specks. He is of medium build and was wearing a pair of green Army-style trousers and a distinctive dark green jacket with the outline of a white tick on the back. He walks with a limp and holds his left arm up against his waist.
Leicestershire Police officers have been carrying out inquiries around the local area and talking to the community for any information on Mr Prosser.
Sergeant Rod Randell, the officer leading the investigation, said: "It has been three weeks since Arthur was last seen by his family and I cannot begin to imagine what they are going through. We are working round the clock to find out where he is and hope that anyone with information about his disappearance will get in touch."