Quick summary –Normally breathing is something which is done automatically – you don’t think about breathing it just happens. When you intentionally focus on your breathing you give your mind something to do and this limits your minds ability to worry, which is often the source of your distress. Breathing is happening in the present moment (as opposed to the future or the past) – when breathing is done intentionally our minds must focus on the present moment (and generally speaking there is often nothing to worry about that is occurring at your present location in the present moment).