There is a strange thing the mind and body have going on. The mind and body communicate and try to stay in sync. Generally the body will do what the mind wants. There is a way to get the mind to do what you consciously want and override the subconscious commands that are being delivered to your body.
Let's say you are hyperventilating because of bad news and you are now having a panic attack. You want to stop breathing hard and want to calm down.
Your body can force your mind to sync up with it. So what you can do is a breathing excessive.