How do you breathe properly when your having a panic attack?

Slow your breathing: When a person has a panic attack, breathing is often rapid & shallow. In other words, they often hyperventilate. I would encourage the person to take slower & deeper breaths.

Breathing with panic: I agree with dr. Fowler -- breaths do need to be slow-er and deeper. It may help to put your hand on your belly, and make sure that when you breathe in, your belly goes out. Breathe out through your mouth with a "whoosh" sound, letting your belly go in again. Practice this for a round of 4 full breaths, at least 3 times a day even when not having panic. Then it'll be second nature for you.

Abdominal breathing: Learn to breath through your abdomen rather than chest. Sit straight and keep one hand on your belly button and other on your chest . Now breathe in but make sure that chest hand does not move and try push out the hand on belly. Practice this several times a day, this is a good way of deep breathing. Now try it when have a panic attack, it will surely help you.