Breathing is, of course, vitally important. However, it could be a major cause of physical pain in parts of your body.
'The connection between dysfunctional breathing and pain is straightforward in principle: if the diaphragm doesn't do its job well, muscles in the upper chest (pectoralis major) and throat (sternocleidomastoid and scalenes) try to take over' (Paul Ingraham).
This can of course cause tension and stress on your body and mind. How to train your diaphragm to work properly and more is explained in the full article here.