Texturing / Unwrapping issue

[detox]

Hello. I would really appreciate it if someone could aid me with this as i have been having worries/troubles with it for a while.

Okay. As i UV Unwrapped my model in blender i realised in texture mode the sides of it was see-through. (i made this model with the mirror modifier if that changes anything) and no matter how neatly i unwrapped it, it stayed there. I looked in object and editmode and it looked fine. Completely normal. I even tried pressing F to add a face and it deleted it, so that must mean they are intact? When i switch to rendered mode they are there and not see through.

My question is: Will it affect my model in the end? ( Should i ignore it and carry on?) or will it make my model messed up.

How do i fix this if it is a problem?

http://postimg.org/image/bzrvat0vr/ Image to show you what i mean. This is an example view from texture mode.

[HellJumper]

Recalculate your normals (select all of your faces in edit mode > recalculate normals).

In the future, use imgur.com as a preferrered image hosting site.

[detox]

Thanks, worked perfectly. And i will! Thanks for the advice.

[HellJumper]

My pleasure!