What is one condition under which a patient is considered incapable of making their own medical decisions?

A patient is considered incapable of making their own medical decisions if they are intoxicated. Intoxication can impair cognitive functions, judgment, and the ability to understand the implications of medical decisions. This condition severely affects the patient's capacity to process information, weigh risks versus benefits, and communicate informed consent, which are all critical elements necessary for making sound medical decisions.

Being fully conscious and alert, engaged in conversation, or seeking a second opinion does not inherently indicate a lack of decision-making capacity. Such states suggest that a patient may still possess the necessary understanding and reasoning skills to participate in their healthcare choices. Thus, the state of intoxication specifically highlights the diminished ability to make informed medical decisions.