Is Paul's "thorn" in his flesh an actual ailment, or a reference to troublesome people “tormenting” his ministry?
Let's begin by looking at the passage.
Paul leaves his ailment intentionally vague, probably because he didn’t want to place the focus on himself. His point in writing was that his supreme revelations had the potential to develop within him great pride, which the Lord counteracted by giving Paul an ailment. Ironically, had Paul spoken specifically about that ailment, he would have been acting contrary to the very purpose for which the Lord assigned it to him.
Therefore, Paul never says what the Lord gave him, and if Paul (and the Lord) desired that the specific nature of his “thorn” remain unspecified, then we should make no attempt to determine it either.