Numbness in the right arm and hand may be caused by cervical spondylosis. When caused by cervical spondylosis, patients mainly show numbness on the ulnar side of the hand and the dorsal side of three and a half fingers, and they may also have numbness in the right arm and right leg, and they may also have motor dysfunction of the right limb, and in severe cases, they may have abnormal sensory and motor functions of the limbs, and they may also have urinary and stool disorders, and they may have urinary and stool retention and urinary and stool incontinence. It is also seen in cerebrovascular diseases, mainly in the basal ganglia area, radiocoronal area, and lacunar cerebral infarction. Patients with cerebral infarction in the basal ganglia region present with right limb motor dysfunction, hemianopia, quadrant blindness, and may also present with speech dysfunction, including aphasia and dysarthria. In case of radiocoronal or lacunar cerebral infarction, most patients can simply present with numbness in the right arm and hand, or simply present with limb motor dysfunction, which can also cause speech dysfunction, hemianopia, and quadrant blindness, etc. Cranial CT examination can make a clear diagnosis.