A diffuse swelling of the scalp in a newborn, usually caused by the trauma of the scalp pushing through a narrowed cervix during birth. the swelling may extend across the midline of the scalp and may exhibit discoloration or bruising.

Caput succedaneum is a benign neonatal condition involving a serosanguinous (containing blood and serum), subcutaneous, extra-periosteal fluid collection with poorly defined margins caused by the pressure on the presenting part of the fetal scalp by the vaginal walls and uterus as the infant passes through a narrowed cervix during delivery. It involves bleeding below the scalp and above the periosteum..