According to a study published in European archives of psychiatry and clinical neuroscience in 2010, falling and being chased are the two most commonly experienced bad dreams. Often, chase dreams include fleeing a threat of some kind, or feeling unsafe. Not surprising if you're dealing with a terrifying boss or a lock on your door that just won't close.

Feeling like you're falling in your dreams is actually a brain quirk, not an emotional thing. If you tend to feel like you're tumbling through space, flying, or weightless, it may be because your body is undergoing a hypnic jerk, in which the brain gets confused about gravity. As you fall asleep, your brain shuts down certain components, including its sense of weight and bodily position. If this part of the brain suddenly wakes up as the body relaxes into deep sleep, it can get its signals scrambled, hence feelings of falling through space. It's scary to wake up from, nonetheless.

A study of bad dreams published in Sleep in 2014 found that stressful dreams often involve some kind of interpersonal conflict. It's no big stretch to see that your brain might re-enact your tense relationships in dream scenarios.

Dreams are often part of emotional processing, though it's not known exactly how they help our emotional health. One study published in Frontiers in Psychology in 2019 suggested that dream experiences can defuse emotional issues we can't deal with in our waking lives, and help us create new scenarios we can control. If you're getting into screaming matches with your boss and dreaming of fights on the regular, it's not a big stretch to see you might need to resolve the tension.

"I happened to play baseball through college, and to this day I have a dream where I need to go on the field and I either can’t find my glove, my hat, or my bat and people are waiting for me to get out there," Fish says. "I've had the same type of dream for over 30 years."

Dreams about lost things and other minor disasters may give us some kind of competitive advantage. A study in Consciousness and cognition in 2014 looked at students about to take a high-stakes exam. The students who had the most intense stress dreams the night before the exam — often involving lost things, lateness, or, in one memorable case, being handed a slice of bread instead of the exam paper — ended up getting higher grades. The researchers told the Guardian they believe this is something called threat simulation theory, in which brains rehearse all the things that can go wrong to help us cope when they do. So when you dream of forgetting your pen and your pants on the day of an important exam, your brain's gearing up to help you deal with something stressful.

Joordens thinks dreams of bugs might relate to abstract fears we have in daily life. "If a concept or feeling is on our minds a lot while we’re awake, it has a higher chance of being one of the things that become active in our dreams," he says. Bugs can relate to fears about viruses, cleanliness, controlling your environment, or worries about your body (or just be a standard yucky nightmare). Want to decode a weird stress dream? Look for fears that might connect to it when you're awake.

Dreaming about earthquakes, hurricanes, or other tragedies Joordens says, is likely a reflection of the increased anxiety we feel during the coronavirus crisis, a natural disaster in and of itself. Harvard dream researcher Dr. Deirdre Barrett has said many people reported dreams of natural disasters during the early coronavirus pandemic in the U.S. in 2020.

These dreams can seem really abstract, but they could make more sense than you think. Stress dreams about bodily issues, like teeth falling out or limbs not working, could reflect worries about illness, lack of control, and loss in waking life.

If you're dreaming that you can't move, it might actually be a reality outside of your dream. You're paralyzed during sleep to stop us hurting ourselves by acting out our dreams. If you wake up and discover that you can't move or speak, it's a phenomenon known as sleep paralysis. Your brain simply hasn't adjusted to the fact that you're awake, and is keeping you immobile. Doesn't stop it being terrifying though.