What must be true for consent to be considered valid?

For consent to be considered valid, it is essential that the consent be voluntary. This means that the patient must provide consent without any coercion, pressure, or undue influence from healthcare providers or other individuals. A voluntary consent ensures that the patient understands their situation and is making an informed choice based on their own values and understanding of the treatment or procedure.

This principle is fundamental in healthcare, as it respects the autonomy and rights of the patient. If consent is not freely given, it could be argued that it lacks the necessary legal and ethical standing, regardless of other factors like whether it is written or witnessed.