Nightmares are unpredictable, but are linked to stress, anxiety, trauma, and more.

What do your dreams mean, according to science

Humans have been interpreting dreams as signs from deities, spirits, or the psyche for ages, and research shows that reflecting on and analyzing one's dreams can be beneficial. In alignment with dreams' elusive nature, they have no objective or clearly assigned meaning. However, variations of common dreams, such as a surprise exam in a forgotten class, are rife with shared primal fears.

Ghost stories across cultures often trace back to traumatic events

From a bat-like demon in Tanzania to a malevolent woman figure hovering above your sleeping body, the four disturbing tales outlined in this NPR article offer a glimpse into how happenings from WWII or the Aztec Empire haunt people’s memories.

Dream interpretation has evolved from ancient mystical explanations, to dream reports, to tracking electrical activity in the brain and more.

Fearology, or the study of fear, explores the difference between stress and fear

Our brains involuntarily respond to our environment and signal alarm when that isn’t always needed, triggering responses that include goose bumps. But understanding fear and how to talk our brains into calming down can improve daily life.

Narcolepsy occurs when the brain loses its ability to control its sleep-wake cycle

Narcolepsy not only makes people fall asleep at random moments, but it can also cause hallucinations, insomnia, and sleep paralysis. The disorder is tied to cells in the brain’s hypothalamus called hypocretin, which are neuropeptides responsible for keeping you awake and controlling your dreaming from coming on too quickly.

Stress is a response to external triggers, while anxiety is persistent and internal

When distinguishing the two, stress is a reaction to identifiable situations like deadlines or conflicts, and its symptoms fade when the stressor is gone. However, anxiety may jump from one worry to another over time without any apparent cause.

Sleep paralysis occurs when the body fails to 'unfreeze' in sync with waking.

A framework for the various potential causes of insomnia

Insomnia typically occurs in people dealing with life stressors and physical or mental health conditions, though the exact cause continues to elude researchers. Generally, the factors can be broken down into external (such as stress, medication, etc.) or internal (neurological) factors.

Why don’t you remember all your dreams?

Despite being a near-nightly occurrence, we remember very few of our dreams. Researchers believe reduced activity in regions where memories are stored, a different neurochemical environment during sleep, and rapid transition during waking contribute to this phenomenon.

Sleep disorders can exacerbate neurological and other health conditions

Brain regions that control sleep sit adjacent to those that regulate the autonomic nervous system, which controls involuntary bodily functions like heart and breathing rates. These neighbors influence each other, meaning poor sleep can impair or negatively impact the ANS, further disturbing sleep.

Pareidolia, the cognitive bias that leads people to find meaning in randomness, helps explain why humans look for meaning in their dreams and even in their tea leaves.

Why do dreamers twitch?

This thought-provoking piece highlights newer research suggesting sleep twitches may not be random dream leftovers, but instead a crucial way our brains map and understand our bodies. From sleeping rat pups to dreaming octopi, this biological mapping system appears universal across animal species.

Dreams have long been used for religious and political power.

NDEs typically change people's outlooks drastically and can prompt depression

The phenomena are regularly categorized as hallucinations, but some specialists are interested in their psychological nuances. Many survivors report feeling less anxiety about death, though some surveys show the experiences can increase physiological sensitivities.

'Those who dream by day are cognizant of many things which escape those who dream only by night.'

- Edgar Allan Poe (1809-1849) in "Elenora"

During dream sleep, the brain connects new information learned during the day with information already stored in the mind, creating a revised mind-wide web of associations.

The benefits of lucid dreaming

Lucid dreams happen when the dreamer knows they've stepped out of the bounds of waking life. Studies show it can help dreamers cultivate creativity, process grief, and work through trauma. A 2021 study found that 85% of participants with PTSD no longer qualified for the diagnosis after a week of trauma-informed lucid dreaming in which they intentionally witnessed (and therefore integrated) recurring nightmares or changed the outcome completely.

Visualizing how we dream via Google search trends

When dreams perplex us, we often want to understand them—and in the age of Google, millions go to its search engine to find answers. Now, researchers have compiled a decade's worth of dream-related queries to glean dream trends across seven languages. See what dream was most commonly searched in Arabic in 2015, or what fears and hopes are specific to one culture and time alone with this unique visual essay.

What it's like to live with insomnia

The biological process Shakespeare referred to as the chief nourisher of life's feast is necessary for the body and mind to rest and repair from the activities of daily life. As sleep evades the exhausted, sufferers also lose emotional stability, mental clarity, social connections, and more while simultaneously gaining waves of interrupted biological processes that can lead to disease and death.

Our ancient fight-or-flight response may contribute to modern ailments

Many common modern diseases humans struggle with may in fact have their origins in our ancient fight-or-flight stress response. Long-term effects of the stress hormones cortisol and adrenaline—in this case, triggered by things like workplace stressors—can wreak havoc on the delicate internal balance of our organ systems.

Dreaming under the Nazi Regime

Days after Hitler seized power, a man told psychoanalyst Charlotte Beradt that he had dreamed of being forced to raise his arm in a Nazi salute ("It took me half an hour to get my arm up, inch by inch"). Beradt recorded this dream and many others so they "might one day serve as evidence." This is an English translation of her work, "The Third Reich of Dreams."

Stress affects different animals in different, but useful, ways

Animals feel stress when they experience actual dangers—such as a zebra chased by a lion. Humans often feel stress from worries, memories, or even thoughts about problems that may occur in the future. For this reason, animals tend to experience stress in short, intense bursts. Conversely, people can feel stressed for long periods, which can eventually be harmful to their health.

Literary theorists distinguish between ‘terror’ and ‘horror’

In her essay “On the Supernatural in Poetry,” gothic novelist Ann Radcliffe defined “terror” as the lurking, unseen specter in a story—something that defined gothic literature. “Horror,” on the other hand, was the explicit portrayal of it. For her, the former was artistic, while the latter was cheap.

A closer look at why people snore

Snoring is simply noise caused by improper airflow during sleep—and while it’s something that most people will do at some point in their lives, it can also be indicative of larger health problems. Generally speaking, snoring occurs when soft...

Sleep research indicates dogs likely dream about their toys, food, and owners.

How your subconscious influences your decisions

How much of your desires and daily choices are truly yours? One of the most effective ways to influence someone's subconscious is when they're asleep. To study this possibility, researchers trained participants to be able to dream lucidly, a phenomenon that occurs when a dreamer knows they're dreaming.

Noise pollution from humans and technology alters animal behavior

Animals may experience chronic stress and health issues due to noise pollution, which often interferes with their mating sounds. Due to traffic, nightingales sing louder on weekday mornings, and birds near airports start singing earlier to avoid upticks in takeoffs and landings.

Obsessing over sleep metrics leads to worse sleep quality

Over one-third of Americans have used wearable technology to track their sleep, and the anxiety over having perfect sleep data, or orthosomnia, has made getting a good night's sleep more difficult. Experts agree that most devices cannot correctly assess sleep details, making the data unreliable.

'Dracula' was inspired by a seafood-induced nightmare

Bram Stoker, the author of the classic horror novel, said that a dinner of "dressed crab" led to unsettling dreams about "a vampire king rising from the tomb." He'd revisit that vision, eventually creating the iconic titular vampire.

Necrosis is the unplanned death of cells and the tissue they comprise

If cells die prematurely due to a lack of blood flow, injury, or disease, they and their organelles can swell, leading to rupture of the surrounding cell membrane. This releases the cell's contents into the surrounding tissue, causing inflammation and damage to neighboring cells.

Consuming true crime media can increase stress and anxiety

Consuming true crime media can activate one's sympathetic nervous system, which controls the fight-or-flight response. Staying in this heightened state of vigilance can lead to stress-related illnesses, including hypertension, and mental conditions, including depression and anxiety. Additionally, people who actively consume crime news, whether they consider it to be entertainment or educational in nature, report being more fearful of crime, regardless of actual crime rates.

Age, stress, and neurological disorders can prevent memory formation and recall

Neurons transmit signals between one another at sites called synapses. Repeated interactions at these sites improve the efficiency of signal transmissions, making memories involving sensory data associated with those neurons easier to recall. Biochemical factors impacting these synaptic interactions affect memory quality.

Panic attacks are intense fear episodes that often occur without a clear trigger

Unlike typical fear responses to real danger, panic attacks can mimic serious health problems, such as heart attacks. Sweating during a panic attack may seem random, but it's a leftover survival mechanism that made it easier for our ancestors to escape by slipping out of an attacker’s grasp.

How burnout alters your brain

Stress is a normal part of everyday life, and it’s not necessarily all bad. But chronic stress—the kind that leads to burnout—can change the size and functioning of parts of your brain. It can alter the ability to make new brain cells and memories and even potentially modify your DNA.

An intense fear must persist for at least six months to be diagnosed as a phobia

Research suggests that both environmental and genetic factors can contribute to the onset of these intense, irrational fears. Often, they can stem from an early traumatic experience, but not always.

Some researchers have labeled nomophobia, the fear of being without your phone, as 'the phobia of the 21st century'

The phobia's name is short for "no-mobile-phone phobia" and was first recognized as a result of 2010 UK government study that found men, in particular, were uncomfortable and anxious being away from their devices.

Sleep training: risks and benefits

Sleep training, which can range from implementing a nighttime routine to letting your baby cry it out, is controversial, but does it work? While dozens of studies have found sleep interventions to be effective, it appears that many of these studies...

Temperature and certain medications can also affect your circadian rhythms

Although light and dark have the largest influence on circadian rhythms, temperature, stress, and certain medications are among the factors that also play a role. Persistent trouble sleeping or staying asleep may signal it’s time to see your doctor to get a better sleep-wake schedule.

Menopause can exacerbate anxiety

Some research shows that menopause can fuel anxiety and also that pre-existing anxiety can boost the chances of experiencing other menopause symptoms, including hot flashes, insomnia, and brain fog. But treatments including hormone replacement therapy, breathing exercises, and other forms of exercise can alleviate some of these symptoms.

Fantasy is a genre that relies on the supernatural

Fantasy is a literary genre that embraces supernatural and magical elements. While the stories often follow common narrative archetypes, like a quest, they frequently take place in elaborately constructed worlds, which sometimes have their own complex physics, lifeforms, and societies.

The human cost of creating medieval monsters

The concept and creation of monsters have been used since time immemorial to communicate social norms and the consequences of breaking them. Some so-called monsters were judged as such solely due to having features that would be considered birth defects in modern times. This in-depth article explores the human cost of creating medieval monsters, many of whom were defined by a physical appearance that deviates from the expected.

'Creepypasta' is a meme that has its roots in folklore

The genre of crowdsourced, horror folklore comes from copypasta, a term that refers to snippets of content copy-and-pasted online ad nauseam. These memes' allure stems at least partly from how they seemingly rise from nowhere, with tales crafted by many hands over many iterations.

The deadly genetic disease that steals shut-eye

Few are haunted by fatal familial insomnia. This neurodegenerative disease is typically carried through bloodlines via genetic mutation of the prion protein gene, forcing the body to create abnormal and pathological protein variations that can corrupt normal versions. This article follows a musician as they attempt to come to terms with the FFI plaguing their family (and, possibly, their future).

Understanding the stages of sleep

Do you have trouble keeping the different stages of sleep straight and organized in your mind? Us too. Sometimes it helps to have a straightforward listing of what each stage is and why it’s important. Look no further than this resource from Lumen. It is a basic outline of the four stages of the sleep cycle, along with the brainwaves and attributes that characterize each. If you’re brave enough, test yourself on the built-in quiz!

Heart attacks are less harmful at night

When heart attacks occur during the day they typically do more harm to the heart tissue than if they occur at night. A 2025 study suggests that daytime heart attacks have higher levels of immune cells called neutrophils to contend with and they appear to worsen the injury. Scientists confirmed this same pattern in experiments with mice. (Some readers may experience a paywall.)

Testing five common beliefs about bedbugs

Bedbugs are one of the most stigmatized pest infestations due to their resilience and tendency to dwell where humans are most unconscious for long periods of time: beds. A bedbug problem can lead to horror stories and intensive interventions to...

PTSD is a long-lasting mental disorder linked to past traumatic events

Posttraumatic stress disorder is a mental health condition arising from traumatic events with four key symptoms: intrusive memories, avoidance behavior, negative moods and thoughts, and changes in emotional and physical reactions.

How the feared self fuels OCD

Obsessive-compulsive disorder is characterized by intrusive thoughts that prompt people to enact compulsions—behaviors intended to relieve the anxiety or stress from the obsession. A significant intrusive thought OCD sufferers endure is the fear they will become a dangerous or immoral person. Therapeutic approaches try to show patients this is just a story that can be set aside.

Nostalgia is a psychological coping mechanism created from bias

Memories are naturally reconstructed during recall, and research has shown a fading effect bias that causes negative ones to fade more quickly, helping us heal. This creates a natural longing for the past, particularly when faced with loneliness, boredom, or challenging moments in the present.

Malaria comes from the Italian term 'mal'aria,' meaning 'bad air'

The term refers to marshy areas associated with the disease. An estimated 94% of malaria cases—215 million—occur in Africa.