الشرك: أن يثبت لغير الله تعالى شيئًا من الصفات المختصة به تعالى
Here shirk is defined as ascribing to another being something that properly belongs to God alone.
The discussion concerns exclusive divine prerogatives such as autonomous dominion, independent knowledge of the unseen, and absolute control over benefit, harm, provision or healing.
A crucial distinction is between ordinary created means and independent divine authority. Human medical treatment or ordinary assistance is not itself a claim to divinity. The question is whether a creature is treated as possessing a power reserved exclusively for God.