David Cartwright, 34, was last seen on September 13 in his home city of Hull.
A Humberside Police spokesman, said: "We are concerned for his welfare as he has some health issues.
"We believe David may have family members in the Leeds area.
"David is 5ft 7in tall and slim with a distinctive tattoo on the left side of his neck. He was last seen wearing a dark t-shirt and baseball cap and dark Adidas shorts.
"Anyone who may know where he is or who have seen him has been asked to call 101 quoting log number 281 of 14/09/17."