The spine is divided into several sections. The first seven vertebrae, labeled C-1 through C-7, comprise the cervical spine. A bulging cervical disk, also known as a herniated or prolapsed disk, can put pressure on nearby nerves. This results in a condition called radiculopathy. If the spinal cord itself is affected, the condition is called myelopathy. Bulging disks often occur as a result of aging, but they can also occur from injury. Symptoms vary depending on which disk is affected.
Pain
While not everyone with herniated cervical disks experiences pain, pain is a common symptom. Pain may be located just at the back of the neck or may radiate down the arm, into the shoulder or into the hand. The location of herniation determines the location of pain. Herniation at C-4 and C-5 causes shoulder pain, while herniation at C-5 and C-6 can cause pain that travels down to the thumb side of the hand, according to physiatrist Richard Staehler, M.D., of the NeuroSpine Center in Wisconsin. Bulging disks in C-6 and C-7, which are the most common locations for cervical bulging disks, cause pain down the biceps and into the middle finger, while herniation at C-7 causes pain down the arm and into the little finger. Flexing the neck or looking up usually increases cervical neck pain, while looking down relieves pain, the Chicago Institute of Neurosurgery and Neuroresearch (CINN) reports.
Weakness
Bulging cervical disks often cause weakness. Weakness from spinal cord compression is more serious than that from nerve compression. Weakness in the shoulder and deltoid muscle in the upper arm often occurs from C-4 to C-5 herniation, while C-5 to C-6 herniation affects the biceps in front of the upper arm and forearm. Bulging of C-6 to C-7 causes triceps, wrist and finger weakness. A bulging disc at C-7 can also cause a weak hand grip. Chronic cervical spinal cord compression can cause difficulty in awaking or paralysis of the lower extremities. Severe cases involve paralysis of all four extremities, according to the Merck Manual.
Numbness and Tingling
Numbness and tingling, or paresthesias, commonly occur in people with bulging cervical disks. Numbness in the shoulder occasionally occurs from C-4 and C-5 herniation, while C-5 and C-6 herniation can cause numbness in the thumb and upper arm. Compression in C-6 and C-7 causes numbness in the fingertips and middle finger, and C-7 compression affects the ring and little fingers, according to CINN.
