Abstract: An apparatus to treat, inhibit, or prevent an indication of a headache symptom in a patient can include a cover, sized and shaped to fit over an eye of the patient to define a cavity between the cover and an anterior surface of the eye when the cover is located over the patient eye. The apparatus can include a pressure source, in communication with the cavity, capable of applying non-ambient cavity pressure to the cavity. The apparatus can include control circuitry, in communication with the pressure source, the control circuitry storing or otherwise configured to define a target cavity pressure value specified to treat, inhibit, or prevent the headache symptom, and configured to control the pressure source to adjust the cavity pressure toward the target cavity pressure value to treat, inhibit, or prevent the headache symptom.