The somatosensory system is an integral component of the motor control system that facilitates the recognition of location and experience of peripheral stimuli, as well as body part position and differentiation. In chronic pain, this system may be disrupted by alterations in peripheral and cortical processing. Clinical symptoms that accompany such changes can be difficult for patients to describe and health care practitioners to comprehend. Patients with chronic pain conditions such as complex regional pain syndrome or fibromyalgia typically describe a diverse range of somatosensory changes. This article describes how sensory information processing can become disturbed in fibromyalgia syndrome and complex regional pain syndrome and how symptoms can potentially be explained by the mechanisms that generate them.