Complex regional pain syndrome and thoracic outlet syndrome can both cause one hand to be warm and the other cold, according to Brain and Westchester Medical Center, respectively. Each condition affects circulation and causes some patients to experience a bilateral temperature difference in their hands.
Traumatic injury of a limb can trigger the development of complex regional pain syndrome, a painful neuropathic disorder, explains Brain. Dynamic abnormal behavior of the skin's vascular system increases the temperature on one side by inhibiting vasoconstriction, and it decreases the temperature on the other side by enhancing vasoconstriction. In thoracic outlet syndrome, the scalene muscles, subclavius muscle, first rib and clavicle create a congested thoracic outlet space that compresses the nerves, vein and artery that pass through it, notes Cleveland Clinic. The vascular compression compromises circulation on the affected side, causing temperature asymmetry, according to Massage Therapy Canada.