Ladies have to wear bra all day and just by night they can release themselves from it. Bras have to be worn properly. I know it seems vary how can there be a improper way of wearing a bra but yes it can cause may problems like lose skin on the back and causing less elasticity of breast muscles.
It is of utmost importance to button the bra below the shoulder blades and also fit your breasts properly in the cups. Bras straps should be tight enough that you can put your finger under them. Watch the following video for further details.