How serious is a disc herniation at c4-c5 with spinal contact?

It could be serious: The two most common levels in the cervical spine to herniate are the C5 - C6 level (cervical 5 and cervical 6) and the C6 -c7 level. The next most common is the C4 - C5 level, and rarely the C7 - t1 level may herniate. C4 - C5 (c5 nerve root) - can cause weakness in the deltoid muscle in the upper arm. Does not usually cause numbness or tingling. Can cause shoulder pain.

Potentially serious: Hope you are under care of an exellent neurosugeon.