Abstract The suppleness of the healthy body provides its basic protection against abnormal blood loss. In movement, tissues slide over each other. Strong tendons and ligaments protect joints. Their lubricated surfaces glide over each other. Healthy muscle and bone respond to the stresses and strains of normal exercise. Muscle tone and bulk protect deep structures, including major blood vessels. The vessels themselves, usually lying loose in these protective tissues, are pushed aside easily on all but the most sudden and severe impacts. When a vessel does break a series of events, known collectively as ‘haemostasis’ (literally static or still blood), begins.