How stress affects every organ in the body

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.

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 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.

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.

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.

Easy resets for stress reduction

Individual solutions for burnout, often called “self-care,” can be helpful for managing stress. Harvard researcher Aditi Nerurkar’s 2024 book The Five Resets details a road map for burnout recovery. In this interview she suggests, among other tactics, gaining focus on what matters the most in one’s life, taking breaks from both work and the internet, and making time for practices that strengthen the mind-body connection.

An interactive guide to the cardiovascular system

The cardiovascular or circulatory system moves blood throughout the body, ensuring cells have necessary nutrients and removing any waste. Click through this interactive 3D guide to explore the system as it crisscrosses the body via arteries, veins, and capillaries. This guide also includes similar breakdowns of the body and its other processes.

Modern workplaces were engineered for efficiency, not work-life balance

Modern work organization traces back to 19th-century scientific management, an approach that optimized output by viewing workers as machine components. That logic still persists today and contributes to burnout, stress, and disengagement. Researchers propose a "circular work" model that combines effort with recovery, learning, and renewal, suggesting productivity and well-being should align rather than compete.

A simple infographic explaining how coral bleaching works

When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white.

Each part of the human body experiences aging differently

With global average life expectancy cresting at 73 years, understanding how the body ages is imperative to effective medical treatment and maintaining a desired quality of life. This 13-minute video dives into how the body and its organs age "from head to toe."

Small ways to improve your health today: an animated guide

What are some ways that you could start making a positive impact on your health today? This animated gallery overviews several health topics, including sleep and hydration, and offers ways to improve that aspect of your life. Clicking on the...

Explore human anatomy with these beautiful images

The Human Organ Atlas offers detailed 3D images of dozens of human organs. It was created with very bright X-rays from a particle accelerator, which is formally called a synchroton imaging method.

Optimal human functioning requires movement

There is now ample evidence to back the centuries-old hypothesis that exercise is critical to human health. This review article explores the latest discoveries in exercise science, including how exercise is intrinsic to maintaining our organ systems throughout life.

How humans digest food

Every day, the average human eats close to six pounds of food—all of which must be processed by the digestive system. Ten organs collaborate to transform food that the mouth chews into the energy needed to stay alive. (Stretched out, these organs...

Visual deep dive into the collapse of insects

The most diverse group of organisms on the planet are in trouble, with recent research suggesting insect populations are declining at an unprecedented rate. Explore this visual interactive on the issue from Reuters Graphics.

See where and how many microplastics are in the average human body

This diagram maps the extent to which microplastics have been found across human organ systems, tissues, and fluids. Beyond the locations shown, microplastics have also been found in the stomach, brain, and sex organs.

Read the WEF’s Global Risks Report for 2025

The Global Risks Report is the World Economic Forum’s annual assessment of the most pressing threats facing the world. The 2025 edition highlights declining global optimism, deepening geopolitical and economic tensions, and rising social fragmentation across societies.

Mental health symptoms may manifest differently across cultures

Mental health, like physical health, is imbued with values, beliefs, and traditions. Symptoms of distress are not universal and may differ based on racial, ethnic, and cultural contexts. Because mental health may be stigmatized or communities may have varying belief systems about causes of mental health challenges and how to fix them, it may affect how symptoms manifest. Chest pain, for example, may be a sign of mental distress—not the need for a doctor.

The science of optical illusions

The human brain has developed cognitive shortcuts to help us navigate in a world where our visual senses are constantly bombarded of information. But these shortcuts can also be exploited, tricking the brain into telling us something is happening when it really isn't. This short video unpacks the neuroscience behind some of the most common (but perplexing) optical illusions.

Explaining the physical connection between the gut and brain

This video overview from Duke University helps visualize the gut-brain axis—a physical connection of nerves running from the brain to digestive tract that acts as a physical and chemical link.

Take a quiz to discover your brain care score

Each year, nearly 800,000 Americans have a stroke. With such a high occurrence rate, you may be asking yourself what you could do now to prevent a future stroke. Researchers at Harvard collaborated to answer this question by coming up with a "Brain Care" scoring system. Take the quiz to learn the quality of your brain health today and pick up helpful insights to lower your risk of stroke and dementia well into the future.

How water pressure affects the body

The extreme conditions of the deep sea include increasing amounts of pressure as explorers and organisms descend into its depths. The major danger for both fish and humans is the way pressure changes how body tissues absorb chemical molecules...

See this collection of mental health cartoons

These cartoons were curated around mental health themes in celebration of World Mental Health Day, which is observed annually on Oct. 10. The 15+ cartoons include thematic nods to weathering mental health challenges and looking forward to better times ahead.

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

Visualizing the global supply chain of medicine

The typical medicine we consume is the end result of a complex global supply chain involving highly specialized compartmentalization. Most medicine was made locally until open trade policies enabled global trade in the 1980s. This visual essay is...

Ebola infects and disables immune cells, triggering a cascade of events that leads to small blood clots throughout the body, weakening blood vessels and interrupting blood flow to key organs.

Explore this week-by-week visualization of pregnancy

This graphic illustrates how development proceeds during each week of pregnancy, tracking what shifts and milestones typically occur during each stage of the process. It also includes typical weights of the fetus throughout.

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

Explore an interactive map built from more than 100,000 survey responses on where people find joy in their lives

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

See these 16 pieces of art evoking phobias of snakes, flying, spiders, and more. 

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts.

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.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

See how each of the more than two million known species relates to each other—and to common ancestors—in this zoomable tree of life.

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

The US dollar is the most widely circulated currency in the world, and is involved in nearly 90% of global transactions

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

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.

Explore the known asteroids, comets, and spacecraft involved in asteroid studies within our solar system with 'Eyes on Asteroids,' a 3D visualization from NASA.

This poison ivy knowledge quiz—accompanied by photos of the plant's varied forms—may help you identify this common rash-inducing growth.

Calculate how much of your tax dollars go to each federal program based on your income, filing status, and number of children

Learn how to read a prospectus, the juicy document that any company must file with the SEC before going public.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

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.

Legendary architect Frank Lloyd Wright designed the SC Johnson headquarters in Wisconsin, aiming to make a cathedral-like workplace

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

The use of fungi to detoxify land and water—a process known as mycoremediation—has been used to clean up natural resources affected by the 2025 California wildfires.

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.

Take a 3D tour of the Hajj, Islam's annual pilgrimage to Mecca, undertaken by over 1.5 million Muslims.