Understanding Shoe Widths
Running shoes tend to be a bit wider than street shoes.
Usually, the lacing can “snug up” the difference, if your foot is a bit narrower. Running shoes shouldn’t be tight because the foot swells during running and walking. On long, hot runs the average runner's feet may swell one-half size. In general, running shoes are designed to handle a certain amount of “looseness”. But if you are getting blisters when wearing good wicking socks and perhaps using an anti friction product like BlisterShield or Foot Goo, snug up the laces a bit more. Several shoe companies make select shoe models in narrow, regular, wide, and extra-wide versions.
Note that Mens and Womens shoe widths vary so if you are not finding what fits well, try different brands of shoes and different width sizes.