A patient interface for sealed delivery of a flow of air at a continuously positive pressure with respect to ambient air pressure to an entrance to a patient's airways including at least entrance of a patient's nares, wherein the patient interface is configured to maintain a therapy pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure in use, throughout a patient's respiratory cycle, while the patient is sleeping, to ameliorate sleep disordered breathing; said patient interface comprising: a plenum chamber at least partially forming a cavity pressurisable to a therapeutic pressure of at least 6 cmH 2 O above ambient air pressure, said plenum chamber including a plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient; and a seal-forming structure having a textile membrane constructed and arranged to form a pressure-assisted seal with a region of the patient's face surrounding an entrance to the patient's airways inferior to a nasal bridge region of the patient's face, said textile membrane having at least one hole formed therein such that the flow of air at said therapeutic pressure is delivered to at least an entrance to the patient's nares, the seal-forming structure constructed and arranged to maintain said therapeutic pressure in the cavity throughout the patient's respiratory cycle in use, wherein the seal-forming structure includes a flexible support structure to hold the textile membrane in a predefined curved shape, said textile membrane including a medial pronasale region an external surface of which having a predefined curved shape with a positive curvature in left-right direction, said textile membrane including a medial subnasale region an external surface of which having a predefined curved shape with a positive curvature in a left-right direction, the support structure comprising silicone, wherein the plenum chamber comprises silicone and is formed in one piece with the support structure, wherein, in use, the textile membrane is configured to press against the patient's face such that the patient's nose is not received in the cavity, and wherein the textile membrane is attached to the support structure along an outer perimeter of the textile membrane such that the textile membrane extends radially inwardly beyond the support structure. a plenum chamber at least partially forming a cavity pressurisable to a therapeutic pressure of at least 6 cmH 2 O above ambient air pressure, said plenum chamber including a plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient; and a seal-forming structure having a textile membrane constructed and arranged to form a pressure-assisted seal with a region of the patient's face surrounding an entrance to the patient's airways inferior to a nasal bridge region of the patient's face, said textile membrane having at least one hole formed therein such that the flow of air at said therapeutic pressure is delivered to at least an entrance to the patient's nares, the seal-forming structure constructed and arranged to maintain said therapeutic pressure in the cavity throughout the patient's respiratory cycle in use, wherein the seal-forming structure includes a flexible support structure to hold the textile membrane in a predefined curved shape, said textile membrane including a medial pronasale region an external surface of which having a predefined curved shape with a positive curvature in left-right direction, said textile membrane including a medial subnasale region an external surface of which having a predefined curved shape with a positive curvature in a left-right direction, the support structure comprising silicone, wherein the plenum chamber comprises silicone and is formed in one piece with the support structure, wherein, in use, the textile membrane is configured to press against the patient's face such that the patient's nose is not received in the cavity, and wherein the textile membrane is attached to the support structure along an outer perimeter of the textile membrane such that the textile membrane extends radially inwardly beyond the support structure.