A cervical radiculopathy is commonly referred to as a pinched nerve in the neck. Basically cervical radiculopathy, "Radic-" is Latin for "nerve root" and "-opathy" pathology, pathology of that nerve root. It is basically irritation of a nerve as it exits the spine.
A cervical radiculopathy will typically present with neck pain radiating down into the arm and sometimes into the hand. The pain is usually more electric, shooting, radiating sometimes it feels like its burning; sometimes people will have numbness, sometimes some weakness in the arm as well.
Diagnosis of cervical radiculopathy begins with a good history and a good physical examination, just like so many other medical problems. Typically, from a history and a physical examination, the doctor will usually be able to determine that a cervical radiculopathy is present or isn't present. Imaging studies, like an x-ray, MRI typically will be able to show the underlying anatomy and show where and how that nerve may be irritated. Essentially, anything that constricts the nerve as it exits the spine can cause a cervical radiculopathy. So, for example, herniated discs; spondylolisthesis, where the vertebral bodies have slipped on top of each other; facet joint arthropathy, where the little hinge joints in the spine get bone spurs and those bone spurs contribute to narrowing of the hole where the nerve comes out. The common denominator here is that the hole where the nerve comes out becomes smaller, and because that hole is smaller, there's less room in the hole for the nerve to exist, and there's more of a propensity towards developing an inflammatory response. And it's that inflammation that typically causes the symptoms of a cervical radiculopathy.
Sometimes if the diagnosis is in doubt, or if the extent of a radiculopathy needs to be evaluated, a doctor can order an EMG, or a nerve test - an electrodiagnostic study that lets you look at the pathophysiology of the nerve and how much or how little it may be inflamed. It can also help to rule out a more peripheral irritation of the nerve as well.