State, region or country law typically defines the issue of who can give consent for medical treatment. People who have this power may vary, though many areas have similar laws. These laws help to protect the rights of an individual from consent by others, which might conflict with best interest. The question is complicated when no recognized authority is available to give consent.
People, who can appreciate the nature of consent and the medical treatments being explained, generally consent for themselves. This group doesn’t include young children or adults who are judged as mentally incompetent. In the case of children, parents or guardians must usually give consent for medical treatment, or in mentally incompetent adults, an appointed guardian, who may or may not be a relative, would need to give permission for treatment. In medical emergencies, when a person is unable to consent due to unconsciousness, consent may not be needed for things like life-saving or preserving treatment, unless an advanced directive otherwise states that life-saving treatment isn’t wanted.
There are some exceptions. First, older children can often give consent for medical treatment of certain types. For example, they may be able to access medical services related to birth control or abortion. Teens may also refuse some treatments, such as sterility, psychoactive medications, or treatments like electro-convulsive therapy. Even though teens may be minors, in some areas of consent they may have primacy consent because of the type of treatment. Similarly, adults with altered or impaired mental status may have power of refusal of some treatments, such as drug, surgical or electroshock treatments for psychiatric conditions.
The stickier question involves who else may consent for medical treatment. As stated, in emergencies, physicians may not need consent for lifesaving treatment of adults or children, but things change if a procedure has risks, is experimental, or may not be proven as absolutely necessary. For children, what happens at this stage may vary. Legal guardians or parents can give consent, but stepparents usually can’t. To avoid this issue, the stepparent can be designated as an additional guardian. Possible other consenters could include adult siblings or grandparents. Parents can create a formal document designating anyone with the power to consent or they can even sign consent away for one-time events like school field trips.
For adults who cannot consent for medical treatment, their spouse can, or a parent may consent if a person is unmarried. Domestic partners have rights to consent in some regions. In some circumstances, siblings can provide permission in emergencies.
However the law is defined, any person may consent if he are she are designated as a medical representative by the individual getting treatment, or if he or she is a medical proxy who is designated by a court. Individuals who know they will reach a point where they cannot consent for medical treatment may also use documents like an advanced directive to designate in advance of treatment which medical interventions they will and will not accept.