We characterize the phase space of all helical Miura origami. These structures are obtained by taking a partially folded Miura parallelogram as the unit cell, applying a generic helical or rod group to the cell, and characterizing all the parameters that lead to a globally compatible origami structure. When such compatibility is achieved, the result is cylindrical-type origami that can be manufactured from a suitably designed flat tessellation and "rolled up" by a rigidly foldable motion into a cylinder. We find that the closed helical Miura origami are generically rigid to deformations that preserve cylindrical symmetry but are multistable. We are inspired by the ways atomic structures deform to develop two broad strategies for reconfigurability: motion by slip, which involves relaxing the closure condition, and motion by phase transformation, which exploits multistability. Taken together, these results provide a comprehensive description of the phase space of cylindrical origami, as well as quantitative design guidance for their use as actuators or metamaterials that exploit twist, axial extension, radial expansion, and symmetry.