The present invention provides a thin-walled PTFE tube with appropriate elongation, sufficient strength, and good uniformity during stretching and a medical tube with excellent flexibility and dimensional accuracy. The polytetrafluoroethylene tube according to the present invention is a polytetrafluoroethylene tube having a wall thickness of about 0.04 mm or less, wherein the wetting tension of either of or both outer and inner surfaces of the polytetrafluoroethylene tube is 46 mN/m or more, and in a stress-strain curve obtained by a tensile test performed under an atmosphere of 200° C., tensile stress at 20% strain σ20 (N/mm2) of the polytetrafluoroethylene tube and tensile stress at 50% strain σ50 (N/mm2) of the polytetrafluoroethylene tube satisfy 2.0≤0.1×σ20+0.3×σ50<5.5 (Inequality (1).