Paraphimosis
A condition in which the foreskin of the penis, once retracted, cannot return to its original location.
The foreskin remains trapped behind the groove of the coronal sulcus between the shaft and the glans.
This causes blood to pool in the veins behind the entrapment, leading to swelling and severe pain.
The foreskin, with lubrication, can sometimes be reduced.
This works only if the paraphimosis is discovered early, and requires a short-acting general anesthetic or heavy sedation.
Circumcision can both prevent and cure paraphimosis