Condition which occurs when a tight foreskin (phimosis) cannot be pulled back over the glans penis; the narrow front end of the foreskin lodges in the groove behind the glans. Obstruction of blood flow then causes the glans and the foreskin to swell, and the foreskin cannot be pulled back into its normal position. The tighter the foreskin the greater the obstruction and swelling. If consulted quickly a doctor can gently squeeze out the swelling and pull back the foreskin; if this is not possible, a small cut in the foreskin can help. To avoid repetition the foreskin may be widened or removed by surgery (circumcision). Paraphimosis can occur during first sexual intercourse in boys and men with a relatively tight foreskin.