Arm pain from a cervical herniated disc is one of the more common cervical spine conditions. It usually develops in the 30-50-year-old age group. Although a cervical herniated disc may originate from some sort of trauma or injury to the cervical spine, the symptoms commonly start spontaneously.
The arm pain from a cervical herniated disc injury results because the herniated disc material “pinches” or presses on a cervical nerve, causing pain to radiate along the nerve pathway down the arm. Along with the arm pain, numbness and tingling can be present down the arm and into the fingertips. Muscle weakness may also be present due to a cervical herniated disc.
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.
The nerve that is affected by the cervical disc herniation is the one exiting the spine at that level, so at the C5-C6 level, it is the C6 nerve root that is affected.
A cervical herniated disc will typically cause pain patterns and neurological deficits as follows:
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.
C5 – C6 (C6 nerve root) – Can cause weakness in the biceps (muscles in the front of the upper arms) and wrist extensor muscles. Numbness and tingling along with pain can radiate to the thumb side of the hand. This is one of the most common levels for a cervical disc herniation to occur.
C6 – C7 (C7 nerve root) – Can cause weakness in the triceps (muscles in the back of the upper arm and extending to the forearm) and the finger extensor muscles. Numbness and tingling along with pain can radiate down the triceps and into the middle finger. This is also one of the most common levels for a cervical disc herniation.
C7 – T1 (C8 nerve root) – Can cause weakness with handgrip. Numbness and tingling and pain can radiate down the arm to the little finger side of the hand.
It is important to note that the above list comprises typical pain patterns associated with a cervical disc herniation, but they are not absolute. Some people are simply wired up differently than others, and therefore their arm pain and other symptoms will be different.