What happens to your body when you watch horror movies?

Along with Halloween comes the abundance of Horror movies in the Tv channels, as well as in cineplexes. Some people relish these movies and binge watch, while others shun them completely. Whether you love or hate horror movies, there's a big chance that you've watched a few of them in your life. And while you've went through a couple hours of horror, your body has changed without your notice.

Sounds scary? Well, there's really not much to worry about.

Why explaining a particularly well-made horror movie, you must've let out a "blood-curdling scream" or at least heard others do it. According to a group of Dutch researchers, no one realized how accurate the term "blood-curdling" is: Fear can literally cause your blood to curdle.

In the study, published in British journal The BMJ, researchers recruited 24 healthy volunteers aged 30 or younger. Fourteen of the volunteers watched a scary movie (Insidious), and then a week later a light, educational movie (A Year in Champagne). The remaining volunteers did the reverse, watching the general movie first, and then the horror one. 

In the research, it was seen that while watching Insidious the volunteers' levels of factor VIII—a protein that plays a role in blood clotting—jumped enough to raise their risk of blood clots. 57 percent of the volunteers experienced the jump, while just 14 percent experienced an increase during the educational movie. 

According to Dr. Thomas E. Eidson DO, a vein disease specialist in Arlington, Texas, there is a good chance we evolved the clotting response when we feel fear. A blood clot is the body's response to injury, and it can slow or stop bleeding. 

"Specifically, a blood clot is a combination of platelets in the blood combined with specific proteins in your blood to form a solid plug to prevent further bleeding." 

"When we are scared, the most primitive part of our brain takes over causing the flight-or-fight response," explains Dr. Eidson. "Our body releases adrenaline, our pupils dilate, and our blood vessels in our extremities constrict moving blood to vital organs and muscles. The body also prepares itself by elevating factor VIII in the blood to increase the body's ability to form clot in case of blood loss or injury." This instinctive response doesn't distinguish between an actual emergency like being chased by a bear, or watching a frightening movie, he stated, so "it responds exactly the same."

However, the study authors concluded that the increase is unlikely to cause actual clot formation. So you can watch your favourite Halloween movie without any worries.