Have you ever noticed a horizontal scroll-bar appearing at your bottom of website.You may look at below image in which horizontal scroll-bar appeared.It makes your website look ugly.The root cause of this problem can be many.
1.One of them is that some section of your website might be displaced towards right while loading,hence scroll-bar is shown.This is basically due to slow internet connection and may be temporary.This specific case may not be seen all the time and depends on internet connection.
2.Size of any of your image or text is not fitting your theme size.
Lets resolve this problem right away as the solution is pretty simple.Though you can reduce the width.But for many it might look complex, if you do not understand the code of your theme and CSS. If you are a developer you can always go to your CSS and correct it.
I am putting here the simplest solution for this,just put below code in body section of your theme anywhere.Remember we are inserting css in HTML code here,notice the top section in below code.
so finally it should go like below
Hope this resolves your problem.If not or if yes, do comment.