While ghosts, goblins, and ghouls may be imaginary, fear is very real.

In honor of spooky season, we’re peeling back the layers of what happens when our bodies go into full “freak out-mode” in frightening situations.

Warning: These facts about fear that could give you goosebumps — without stepping into a haunted house.

1. Your brain gets “fight-or-flight” ready

When something scares you, your brain kicks into high gear. The sympathetic nervous system (responsible for the fight-or-flight system) goes into overdrive and decreases the functions of your brain’s frontal lobe (responsible for logical thinking and planning). Read: The more animalistic parts of your brain take over.

This could mean your heart races, your breathing quickens, and suddenly, you’re on high alert. It’s like your body’s own horror movie scene — but instead of escaping zombies, you’re running from stress.

2. Anxiety happens when worry takes over

Anxiety is like fear’s sneaky cousin. While fear is a response to an immediate threat, anxiety is more of a lingering unease about something your brain thinks is dangerous (but often isn’t). It creeps in when you’re anticipating the unknown, like worrying about a big presentation or an unexpected phone call.

Unlike fear, which triggers a short-term response, anxiety can hang around longer, keeping your body in a state of heightened alert. While some anxiety can be helpful, constant fear should be tackled through methods like therapy, medication, or both.

3. Fear is a built-in survival tool

Fear might make your knees shake, but it’s not all bad. Our fear response is designed to help keep us safe. In prehistoric times, fear helped our ancestors avoid life-threatening situations (think: saber-toothed tigers instead of Halloween vampires). Today, it still helps us stay safe by making us more aware of our surroundings.

Now, we hope you feel more prepared to face those Halloween frights — both real and imaginary.