Dutch researchers have found that scary movies really are blood-curdling, NBC News reported.
A team from Leiden University Medical Center found that the fear induced releases a little blood-clotting protein called Factor VIII. The team studied 24 volunteers aged 30 and younger.
Blood samples were taken before and after each volunteer watched and rated two films — a horror and a documentary.
The horror movie produced higher levels of the protein in 57 percent of the volunteers, while it dropped for most of the volunteers watching the documentary.