Written or spoken permission to proceed with care is classified as:

Expressed consent refers to the clear and explicit permission given by a patient or their authorized representative for a healthcare provider to proceed with a specific medical treatment or intervention. This type of consent can be provided in writing or verbally and is an important part of the legal and ethical framework governing patient care. By obtaining expressed consent, healthcare providers ensure that patients are fully informed about the risks, benefits, and alternatives of the procedure or treatment, thereby respecting their autonomy and right to make informed decisions regarding their own healthcare.

In contrast, advanced directives typically refer to documents that outline a person's wishes regarding medical treatment in the event that they become unable to communicate these wishes themselves. Formal consent often denotes a more structured process, which may require additional documentation or legal considerations, while implied consent usually applies in situations where it is reasonably assumed that consent has been given based on a patient's actions or the circumstances surrounding care, even without explicit communication. Expressed consent is vital as it establishes clear and intentional agreement regarding the proposed medical actions.