The differential diagnosis for upper-extremity numbness includes a wide spectrum of disorders ranging from central nervous system conditions to peripheral nerve compression. Accurate localization is paramount, as the treatments for the numerous causes vary widely. Although the differential diagnosis is large, there are many common conditions that cause upper-extremity numbness, and providers should be familiar with them. With regard to peripheral compression neuropathies, carpal tunnel syndrome is the most common peripheral nerve entrapment syndrome, with an estimated prevalence of 3.7% in the general population, followed by cubital tunnel syndrome, the second most common upper-extremity peripheral nerve entrapment syndrome1,2. Additionally, spinal pathology resulting in cervical radiculopathy presented with symptoms of upper-extremity sensory changes in 85.2% of 736 patients and diminished sensation correlating with the level of pathology in 65% of 100 patients at the time of the surgical procedure.