Can be an emergency. Phimosis refers to narrowing of the foreskin so that it cannot be retracted over the glans penis (head). Paraphimosis is the state in which a narrowed prepuce, foreskin, is forcibly retracted over the glans and now cannot be un-retracted. If the prepuce opening is too small, it may block the blood supply to the glans, necessitating emergent surgical correction. Phimosis - needs circumcision.