Which document typically serves as a guide for medical decision-making during serious illness?

A living will is formulated to provide guidance on medical decision-making during serious illness, particularly concerning end-of-life care. It outlines a person's preferences for medical treatments and interventions when they are unable to communicate their wishes due to their condition. This document is essential for ensuring that healthcare providers and family members understand the individual’s desires regarding life-sustaining measures, resuscitation, and other critical treatment options.

In contrast, while a power of attorney for finances can appoint someone to handle financial decisions, it does not address healthcare preferences or medical treatment. A healthcare insurance policy relates to coverage for medical services and does not serve as a directive for specific medical decisions. Similarly, a medical history form is primarily for documenting past health issues and treatments but does not provide guidance on future medical care preferences. Thus, the living will is uniquely positioned to serve as a guiding document during serious health situations.