John Barrett has been missing for four weeks, prompting West Midlands Police to launch an appeal to find him.
The 35-year-old went missing from his home in the West Bromwich area on May 29, and police have released several appeals to trace him since.
He has type 1 diabetes and it is believed that he hasn't got his medication with him.
It is not thought that John has left the Sandwell area.
John is 5ft 9ins tall, has short brown hair and was clean shaven when he went missing.
He was last seen wearing white tracksuit bottoms, a black coat and blue trainers.
Anyone who sees him is asked to call 999 immediately.
Those who have any more information on his whereabouts, or any footage of anyone believed to be John, is asked to contact West Midlands Police via live chat on its website, quoting PID 390053.