Haemorrhage is a medical term that refers to excessive bleeding or blood loss. It can occur internally, such as when a blood vessel bursts and causes significant blood loss within the body, or externally, such as when an injury causes bleeding from a wound. The word "haemorrhage" comes from the Greek words "haima," meaning blood, and "ergon," meaning work. Therefore, haemorrhage literally means "to do excessive work in respect of blood."