The patient has the right to express his or her consent to accept defined health services or to refuse them after having been granted appropriate information. The consent of the patient - and in the case of minor patients or persons incapable of expressing their wishes the consent of the legal representative or sometimes of the guardian-in-fact or guardianship court - is the main basis for a physician to act.
The physician must obtain the patient's consent not only for therapeutic interventions but also for those which are of a diagnostic nature.
The consent has to be distinct, and in the case of interventions which mean a risk higher than average shall be in writing. The Law on the Physicians' Profession stipulates that a physician may only perform an operation or apply a treatment or dianostic method, creating an increased risk for the patient, if he has obtained tht patient's written consent. However, the patient's consent does not need to be granted every time in writing. According to almost the entirely shared interpretation of the doctrine, the consent can be given orally and even can be presumed from the facts in the case of interventions with normal risk. The consent has to be sufficiently distinct.
The fact that the consent has to be given in writing when the risk is higher than average is a formal requirement for evidential purposes (ad probationem). The burden of proof that an informed consent was given rests on the physician.
There is no provision with regards to the withdrawal of consent in the case of a normal medical treatment.