Devices, systems and instructing methods for treating medical conditions in patients include a handheld non-invasive nerve stimulation device. The device includes a container filled with electrically conductive fluid and one or more energy transmitters surrounded by the conductive fluid. The container comprises a contact surface configured for contacting the outer skin surface of a neck of a patient for delivering electrical impulses from the energy transmitters through the conductive fluid and the patient's neck to the vagus nerve. The electrical impulses are sufficient to treat the medical condition of the patient.