Stress contributes to gray hair because when the body experiences stress, the sympathetic nervous system releases specific hormones that influence pigment-producing cells.

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.

Stress activates the "fight-or-flight" response when we face threats, a reaction that can help keep us alive.

Stress and the brain

While an acute stress response is a normal bodily function, the effects of chronic stress can be extremely damaging to the human body. This is particularly true with regard to the brain. This article explores the effects of stress on the human brain, including how chronic stress may lead to psychological conditions such as depression and memory loss.

Stress can be contagious—and scientists want to learn more about it

Researchers have shown that being around someone who is stressed can trigger a stress response in your body, such as elevated cortisol levels and elevated heart rate. One way this was recently studied was by having people watch stressful activities, like a recorded job interview or solving challenging math problems, and then sampling hormones in observers' spit.

The biology of stress in your body

Stress is a normal human response that has evolved over millions of years to handle changes or threats in our environment. This article is a helpful overview of the biological basics of this response. While it is not harmful to our physiology in the acute setting, chronic stress can lead to damaging changes in the human body over many years.

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.

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.

How we frame stress—as good or bad—seems to alter how it affects us

This podcast discusses research that indicates stress perception may drastically affect how we respond to it. In research exploring if our stress is presented as diminishing our health versus if we're told it enhances our performance, it will lead to differences in how successful participants are at performing tasks—with the enhancers doing better.

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.

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.

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.

The positives of feeling stressed

Worrying about past events and upcoming challenges is not a pleasant experience, but a reasonable amount of stress can bring a lot of good into our lives. In this episode of "The Happiness Lab" with Dr. Laurie Santos, two psychology experts offer tips for resetting one's relationship with stress. Listen and learn how to make stress a positive tool rather than a debilitating emotion.

Too little stress can also harm our health because mild or moderate stress—followed by recovery—helps make us resilient.

Grief rewires the human brain

The human brain handles stress and emotional traumas similarly. In response to the emotional stress of a situation like the death of a loved one, divorce, or abuse, the brain may strengthen or weaken connections between nerves to form new neural connections. Over time, chronic stress can diminish brainpower, reducing overall nerve growth and memory to shift resources to enable elevated fear responses and enable humans to survive.

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.

Telogen effluvium is a common, temporary type of hair loss that can be triggered by severe stress, illness, or other body changes like childbirth—it pushes as much as 70% of hair into its resting phase, causing hair to fall out.

Rodent research suggests goose bumps may play a role in hair growth—raising questions about if this knowledge could be used to reactive sympathetic nerves in hair follicles to boost hair growth in people.

Why does the body have a stress response?

When encountering a stressful situation, the human body typically goes into what is known as "fight-or-flight" mode. Because it evolved as a survival mechanism, the biochemical response enables people and other mammals to react quickly to life-threatening situations. The carefully orchestrated yet near-instantaneous sequence of hormonal changes and physiological responses helps someone to fight the threat off or flee to safety.

How stress affects every organ in the body

If you are a visual learner, this resource is for you. Not only does this article from the World Economic Forum outline the causes of modern stress along with helpful strategies, but they have created an approachable infographic to show exactly how stress manifests throughout our different bodily systems. Pair this visual guide with our other resources to gain a deep knowledge of stress and the human body.

Male pattern baldness is not solely inherited from the maternal side; its causes are still under investigation, but scientists think the genetic component of this type of hair loss involves multiple genes.

Some types of stress (eustress) have positive benefits

While many perceive stress as solely negative, stress can in fact be divided into two categories: distress (negative stress) and eustress (positive stress). Moderate levels of stress are positive in that they can boost motivation and promote resilience, which have positive mental health benefits.

Aging explained with Dr. Nick Golinvaux

Aging is more than wrinkles and gray hair—it’s a gradual decline in cellular function. Over time, DNA damage, telomere shortening, and mitochondrial inefficiency contribute to weaker bones, slower memory, and reduced vitality. While aging is inevitable, regular exercise, quality sleep, and stress management maintain health and extend one’s years.

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

Music that builds to a crescendo and then resolves relieves stress more than listening to nature sounds

How aging degrades neural functioning in the brain over time

Aging affects the brain perhaps more than any other organ in the body. Throughout life, the brain experiences radical shifts in the number of neurons, synaptic connections between neurons, and hormone levels that regulate our mood and processing.

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.

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.

The two phases of stress: fast and slow

The physiological response to acute stress generally involves two phases—the "fast" response in which adrenaline is released, and a second "slow" response in which cortisol is released. This technical resource reviews what happens in the body during each phase.

Real-time tracking of individual hair cells has revealed that hairs don't actually get pushed out from the root—instead, hair cells are tugged upward by surrounding tissues that act like tiny motors.

Gut microbiome experiments involving transfers of gut microbes from depressed people to rodents indicate that the rodents may then display depression-like symptoms.

What employers can do about parental stress

The US Surgeon General recently released a formal warning deeming parental stress a public health issue. The advisory also included recommendations for how employers can mitigate the issue. Employers can help their employees access child care, for instance, or provide flexible working hours. To find out more about what the Surgeon General prescribes, read more here.

Exercise improves brain blood flow, stimulates neural growth, and more.

The second phase of acute stress: the 'slow' response

The body's reaction to acute stress involves two responses: fast and slow. The first occurs immediately, with the central nervous system triggering the release of adrenaline. The second releases cortisol, which elevates blood sugar and blood pressure and restricts nonessential functions like digestion and the immune system.

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).

During the fall, shorter days trigger cells in leaves to produce less chlorophyll, a green pigment that is typically present in sufficient concentrations to mask other pigments, such as yellow and orange.

Humans may have as many as 100,000 to 150,000 individual hairs on our scalps, growing at a rate of roughly 1 centimeter per month.

40% of women will have noticeable hair loss by age 50.

Consuming true crime media can increase stress and anxiety and create a false sense of danger.

Cold water swimming can induce positive stress

The tradition of cold water swimming (or taking a cold plunge, or even a cold shower) has been shown to release the same hormones triggered during a stress response. This can have the effect of increasing blood flow, improved mental acuity, and more.

Some sounds that have been shown to affect mood and noise have been given color names, such as brown, pink, and green noise, corresponding their frequencies to those of light.

How do anxiety and stress differ?

This article explains that though “stress” and “anxiety” are often used interchangeably, there are distinct differences between the two. Stress is defined as the body's response to an external trigger and can be classified as acute or chronic. Anxiety, however, tends to be triggered internally by excessive thoughts and judgement. Whereas stress disappears when the trigger is gone, anxiety tends to stick around. If left unchecked, both can escalate into more severe mental health conditions.

Exercise releases chemicals that enhance cognitive function

Neurotransmitters like dopamine, serotonin, and norepinephrine, along with increased brain-derived neurotrophic factor levels, enhance a wide range of brain functions. New research demonstrates a direct link between movement and numerous cognitive benefits, including memory, learning, and stress resilience.

How depression affects the brain

Treatment for depression has historically hinged on the theory that the condition was caused by underactive or abnormal neurotransmitters, specifically serotonin and norepinephrine. This four-minute video by Yale Medicine details how these neurotransmitters didn't explain the symptoms of depression but, two other neurotransmitters involved in regulating mood and emotion did. GABA and glutamate, some of the brain's most plentiful neurotransmitters, may possibly be the source of depressive symptoms.

Can humans delay or reverse old age?

We're not sure yet. Researchers at the University of California San Francisco are studying why some conditions and behaviors, such as low-oxygen environments and exercise, benefit the aging process, hoping to reveal potential health applications. Some of this research focuses on klotho, a naturally occurring age-regulating hormone named after the Greek Fate Clotho. Animal studies on klotho brain injections found subjects had improved memory recall and age-related degeneration resistance.

Goose bumps are often triggered by emotions

A physiologist and professor of zoology explains that the subconscious release of adrenaline, a stress hormone, causes a contraction of skin muscles. It’s released in several situations, including when humans are cold, afraid, or feel strong emotions. (Some readers may experience a paywall.)

JJ Schildkraut theorized depression is linked to brain chemical imbalances—in 1965

Schildkraut was one of the first to put forward this idea, which stemmed from lab animal research. A decade later, researchers published the first landmark paper on fluoxetine—better known by trade name Prozac—which increases serotonin levels in the brain.

High-powered red light therapy—delivered directly to nerve fibers via a fiber optic needle—has been used in recent experimental research to suppress pain.

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.

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.