A petechial hemorrhage is a tiny pinpoint red mark that is an important sign of asphyxia caused by some external means of obstructing the airways. They are sometimes also called petechiae. Their presence often indicates a death by manual strangulation, hanging, or smothering. The hemorrhages occur when blood leaks from the tiny capillaries in the eyes, which can rupture due to increased pressure on the veins in the head when the airways are obstructed. If petechial hemorrhages and facial congestion are present, it is a strong indication of asphyxia by strangulation as the cause of death.

The forensic pathologist usually needs a very good light source and maybe even a magnifying glass to detect petechial hemorrhages. They range in size from the size of a speck of dust to around two millimeters and may occur in distinct groups. Often they are seen in the conjunctiva of the eyes and also on the eyelids, especially after hanging. They...