James Slater, 73, was last seen July 20 in Wabamun, Alta. ((RCMP))

RCMP are requesting the public's help in finding a missing 73-year-old man from central Alberta.

James Slater was last seen July 20 at 10:30 a.m. when he stopped at a store in Wabamun, about 65 kilometres west of Edmonton.

His family is concerned because he suffers from depression and diabetes and is at high risk for a heart attack, but didn't take his medication with him when he disappeared, police said.

Daughter Cindy Bedford said it's horrible not knowing whether her father is all right.

"It's killing us. It's killing us. We get through day to day," Bedford said.

"You stay with your routine, because you have to to get through the day, but this is.... We just don't know. We just need to find him."

Slater is about 5'10" tall and weighs 160 pounds. He has brown eyes, thin grey hair and a white mustache.

He was last seen wearing grey pants, a polo shirt, a blue and black plaid jacket and a blue hat.

Slater was driving a blue 1992 Ford Econoline van with Alberta licence plate number NYA 165.