informed consent, in medicine, a patient's written consent to a surgical or medical procedure or other course of treatment, given after the physician has told the patient all of the potential benefits, risks, and alternatives involved. Informed consent is also required for participation in clinical studies. The concept of informed consent is based on the principle that a physician has a duty to disclose to a patient information that allows the patient to make a reasonable decision regarding his or her own treatment. There is debate over whether special populations, such as children and the mentally ill, can really be considered to have given informed consent.

consent, in law, active acquiescence or silent compliance by a person legally capable of consenting (see age of consent). It may be evidenced by words or acts or by silence when silence implies concurrence. Actual or implied consent is necessarily an element in every contract and every agreement. In criminal charges, the consent of the party injured (if not obtained by fraud or duress) is a defense for the accused, unless a third party or the state is injured.

age of consent, the age at which, according to the law, persons are bound by their words and acts. There are different ages at which one acquires legal capacity to consent to marriage, to choose a guardian, to conclude a contract, and the like. For marriage, the age may be higher for males than for females if the jurisdiction does not guarantee equal rights to men and women. Age of consent also means the age below which consent of the female to sexual intercourse is not a defense to a charge of rape. Under common law this age was 10; state statutes in the United States generally set it between 13 and 18. See also consent.