What causes subgaleal hemorrhage?

Subgaleal hemorrhage is caused specifically by the rupture of emissary veins, which are small veins located in the scalp that connect the superficial veins, responsible for draining the scalp, with the venous sinuses in the cranium. This rupture often occurs due to excessive traction on the scalp, which can happen during delivery in neonates or from trauma in older children or adults.

When these emissary veins rupture, blood can accumulate in the subgaleal space, leading to significant swelling under the scalp and potentially serious complications if not recognized and managed promptly. This condition is particularly concerning in newborns as it can lead to significant blood loss, hypovolemia, and even shock if not treated.

Choosing the correct cause of subgaleal hemorrhage emphasizes understanding the anatomy and physiology of the scalp and the implications of trauma or delivery techniques that may increase the risk of such a bleeding event.