Stress-induced hormones contribute to gray hair

Stress-induced adrenaline can trigger a 'hysterical strength' response

The stress response is a powerful ancient mechanism designed to maximize human survival—it can even result in superhuman strength. The adrenal glands are located just above the kidneys, and stress-induced adrenaline release causes more blood (and therefore more oxygen) to flow to your muscles, increasing performance.

DNA damage and chemical stress causes cellular aging

While outward signs of aging, like gray hair and wrinkles, are easy to spot, aging changes at the cellular level are less obvious. The decline within cells stems from numerous sources, including DNA damage, oxidative stress, and accumulated waste.

Chronic stress affects nearly all parts of the body

Stress is our body’s internal mechanism to deal with changes in our internal balance. As such, the stress response affects nearly every organ system through a cascade of both fast and slow hormonal changes. While short-term stress can be adaptive, long-term stress may cause serious health issues.

Fear (and stress) can be contagious via pheromones secreted by the body

While seeing someone else in a panicked state may induce a stress response, researchers have found stress can be literally contagious—chemicals contained in sweat and other secretions can trigger stress hormone release in others. Theories suggest this feature is an evolutionary adaptation to protect groups from danger.

Prolonged stress impairs the prefrontal cortex

Burnout isn't just a feeling—it physically affects the brain. Prolonged stress impairs regions of the brain responsible for decision-making, emotional control, memory, and more. It can also lead to chemical imbalances, like reduced dopamine and norepinephrine levels, that worsen these effects.

Goose bumps may play a role in hair growth

Research in mice suggests that the same muscles that contract to create goose bumps act as the bridge for the sympathetic nervous system’s connection to hair follicle stem cells. This raises questions about how this knowledge could be used to reactivate the sympathetic nerves in hair follicles to boost hair growth in people.

Red blood, skin, hair, and nail cells destroy their DNA upon maturing

To maximize the amount of oxygen they carry and more easily alter their shape to fit into narrow blood capillaries, red blood cells destroy their own nuclei. Cornified cells found in hair, nails, and the outermost layer of skin destroy their nuclei and other cellular contents to make room for keratin, which provides durability and structural support.

Short-term cortisol spikes can boost the immune system

Elevated acute levels can enhance the immune system's ability to fight off infection or respond to injury. Chronic heightened cortisol levels, however, can lead to inflammation that harms cells and tissues over time.

A man’s genes can predict his hairline

There’s actually some truth to the idea that you should look at your mother’s father. But genetic research tells us that the full picture is somewhat more complicated. An interesting read on how to use genetics to figure out if you'll go bald (with illustrations).

So-called 'recession blondes and brunettes' skip hair appointments to save money

One hairstyle trend is seen as a recession indicator: people letting their hair grow darker roots instead of frequently splurging on expensive blonde highlights.

A pregnant woman's brain sheds gray matter, perhaps explaining 'baby brain'

The brain areas involved in processing information and emotions decrease by an average of almost 5% during pregnancy. Researchers discovered in a 2025 study that this mostly temporary change—the brain hadn't fully returned to its normal size six months after pregnancy—seems to be associated with self-reported improved bonding and less hostility toward the child postpartum.

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.

Copper is responsible for turning blonde hair green in swimming pools

Pools use copper sulfate to control algae, which can bind to hair either damaged by the sun or recently bleached. Chlorine, which is often considered to be the culprit, weakens the hair structure to exacerbate the green coloration reaction, rather than causing it.

Some data shows cold showers can help with depression

An icy water exposure can lead to the release of norepinephrine, cortisol, dopamine, and other stress hormones that are beneficial, among other potential effects. Some data shows that this type of exposure can help combat depression symptoms among some patients, but more research is still needed. (Some users may encounter a paywall.)

How menopause affects mental health

Menopause, a natural biological process, occurs in three stages: perimenopause (hormone fluctuations), menopause (end of menstrual cycles), and postmenopause (12 months without menstruation). Hormonal shifts during this time can affect neurotransmitters, increasing the risk of mood disorders.

SAD disrupts melatonin secretion, producing it longer in the morning

The hormone is secreted from the pineal gland in the brain and is key to the timing of sleep. However, the substance does not generate sleep itself. With seasonal affective disorder, the body misperceives the photoperiod—the time with light—and the cycle of sleeping and waking gets off-phase, leading to issues with circadian rhythms.

Diabetes is a hormonal disorder

Hormones are naturally produced in the body in concert with cell receptors, influencing how cells behave, but diseases that affect hormonal production, including those produced by the pancreas or the thyroid, can upend those processes.

Developing adaptable brain-body systems lets athletes thrive beyond 30

Success in high-level sports after age 30 relies on physical fitness and building brain resilience through deliberate training, recovery, and stress regulation. This creates a feedback loop where body and mind reinforce each other.

The science behind why some noises have color names

Different noise colors (white, brown, pink, blue) have been proven to affect mood and focus. An audiologist explains that these sounds are named after specific light wave frequencies. While individual preferences vary, certain noises consistently impact sleep, stress reduction, cognitive performance, and problem-solving. The article highlights how these sounds can enhance productivity, relaxation, and even gaming experiences.

Watch how your nervous system's efforts to process silence can contribute to tinnitus

Cochlear cells can be damaged in numerous ways, including aging or exposure to loud noise. If enough cells die, the auditory system can become less sensitive, prompting the brain to compensate by amplifying sound, which is likely to contribute to tinnitus.

How the body produces its own opioids

Opioids act on the body's own opioid receptor system. The endogenous opioid system comprises four molecule receptor types found throughout the body. When activated, these receptor types trigger the release of dopamine and suppression of noradrenaline, neurotransmitters, respectively, associated with reward and alertness. This opioid system helps regulate emotions, and its disruption is linked to neuropsychiatric conditions, including depression, PTSD, and Alzheimer's disease.

Psychiatrist Bruce Greyson created a scale to identify and rate NDEs

Researcher Bruce Greyson is one of the world’s leading experts on near-death experiences. This article explores what the field of NDE research has learned over the last five decades, discusses the difficulties of studying such a controversial topic, and outlines what we’ve ruled out as the cause of these events.

Schizophrenia symptoms, like psychosis, often first emerge among young adults

A combination of genetics, significant brain changes to the frontal cortex, and hormonal changes during young adulthood—late teens to early 30s—result in schizophrenic symptoms often showing up during this period. The stress of life changes at that age may also be a contributing factor.

How the pigments that absorb light for photosynthesis contribute to plants' green color

Although light energy is captured to power the reactions that produce the building blocks of starch, cellulose, glucose, and other sugars, chlorophyll a and b are most sensitive to violet, blue, orange, and red light, leaving green light mostly unabsorbed. This green light is instead reflected, giving most plants this color appearance.

Remylination is a huge focus for treatment—especially among older adults

Our ability to build new myelin sheaths for nerves degrades with age. There have been research advances boosting cells that support these processes and clear away debris from degraded myelin, but not yet any medications to boost myelination itself, which would aid nerve signaling and preserve nerve function.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

Poison ivy will likely become both larger and more resilient due to climate change.

The hormonal disorder PCOS was renamed PMOS in 2026, a move designed to improve care and research by shifting the focus to the hormonal causes of this condition that affects 1 in 8 women.

Tattoos remain visible on your skin thanks to immune cells called macrophages

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

In recent years a child anxiety expert has created and tested a novel phobia and anxiety treatment approach for children, focused on changing how parents respond to the fears.

Coral reefs get their colors from zooxanthellae—microorganisms that line corals' digestive tracts and provide them with sugars in exchange for a home within this protective tissue.

Some renewable energy sources may weaken the resiliency of electric grids by removing outage buffers provided by coal- and natural gas-fired plants, which provide the system with more time to find a new power source if a plant goes down.

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

Astronauts have repaired genetic damage in space using CRISPR—a molecular tool that can make precise changes to DNA and is used in single-celled organisms to attack invasive viruses.

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

Power lines are dotted with large, brightly colored balls to improve the visibility of these thin wires to helicopters and small planes and help prevent potential crashes.

Play the role of a student in a game where you try to navigate college and remain debt-free, selecting different income levels, high school experience, race, ethnicity, and more.

Clever Hans was a 1900s horse that was believed to be able to solve math equations, tell time, and read and comprehend German, until a psychology student discovered how he got his answers.

Prince's sexually explicit 1984 track 'Darling Nikki' attracted the ire of the Parents Music Resource Center, an advocacy group that inspired the Parental Advisory sticker, even though the song ends with a Christian message.

When a Paris department store hesitated to sell Estée Lauder's perfume, she 'accidentally' broke a bottle, causing the smell to spread throughout the store and shoppers to start asking to buy the scent.

Neutron stars, the remains of some massive stars after they explode in a supernova, are the densest directly observable objects in the universe.

In 1939, baseball star Lou Gehrig delivered his inspirational 'Luckiest Man' speech after retiring due to the health condition that now bears his name.

Brandi Chastain, the star of the 1999 US victory over China in the 1999 Women's World Cup, was a last-second choice to take the penalty kick that sealed the victory.

The power and influence of the American presidency have expanded significantly over time—far beyond what the founders envisioned.