Thorn in the flesh
Thorn in the flesh is a phrase of New Testament origin used to describe an annoyance, or trouble in one's life, drawn from Paul the Apostle's use of the phrase in his Second Epistle to the Corinthians. And lest I should be exalted above measure through the abundance of the revelations, there was given to me a thorn in the flesh, the messenger of Satan to buffet me, lest I should be exalted above measure.