An unhealthy tension in our diaphragm

The diaphragm is an unconscious muscle, we can speak about tension in other muscles.
Tension in shouders, neck, is hard to get rid of, move it a bit, try to be aware of yourself tensing up, and let go.
Sounds easy but is hard to do, specially when singing high notes.

@hollow_kurosaki88 What Max means is that we cannot consciously control the diaphragm. It just does what it is "programmed" to do - allows us to breath. Unlike our biceps for example, which we can contract and relax at will, and hold in either state, the diaphragm contracts and relaxes at-will simply by taking a breath and releasing that breath. Outside of breathing, we cannot actively engage the diaphragm.