How much should your doctor tell you?
Well, everything material, if you ask. And if you do not ask?
The doctor should inform you of the treatment it is proposed to apply to you and clearly inform you of any risks associated with that treatment. The presumed outcome of that will be an “informed consent”.
It is only with the consent of a patient that a surgical procedure, say, is rendered lawful. Without the consent it is an assault and battery and a particularly serious one at that.
A consent which is not informed is not a real consent.
The limitation on the duty of disclosure is the word “material”.
A doctor, even using an information sheet or publication, cannot be expected to inform every patient of everything relating to the proposed treatment. There would not be enough time in the world to achieve that objective.
Nevertheless, it is not enough for a doctor to say that he/she replied to the queries of the patient; in short that “informed” standard varies from patient to patient, depending on the inclination of the patient to ask questions.
In Geoghegan v Harris , Kearns J stated;
Having regard to the heavy obligations imposed on medical practitioners by Walsh -v- Family Planning Services , it seems to me that any real consideration of the “inquisitive patient” is subsumed by the onerous obligations of disclosure set down by the Supreme Court. Current Irish law requires that the patient be informed of any material risk, whether he inquires or not, regardless of its infrequency.”
This is a deviation from what appears to be the UK approach, an approach obliquely queried by Sedley L. J. in Wyatt v Curtis  EWCA Civ 1779 where he said;
…there is something unreal about placing the onus of asking upon a patient who may not know that there is anything to ask about”