What is cardiovascular disease?

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.

Why vascular dementia develops

This type of dementia, the second most common form after Alzheimer's, develops due to microscopic bleeds and blood vessel blockages in the brain. The condition isn't curable but medications to help with blood clotting and high blood pressure are part of a suite of interventions designed to minimize damage to the brain.

Diabetes has downstream effects on the heart, eyes, kidneys, and more

High blood sugar levels in untreated diabetes roughen artery walls, increasing plaque buildup, heart disease, and high blood pressure risk. High levels also cause acid to build up in the bloodstream, potentially making the brain swell, the lungs fill with fluid, and the heart to beat arrhythmically—all fatal complications.

The earliest known cardiovascular system dates to 520 million years ago

The earliest evidence of a cardiovascular system and blood-like substance may date back to the Cambrian period in an ancient arthropod. This 2014 academic article includes images of the ancient cardiovascular system, which remains one of the most detailed samples of Cambrian arthropod anatomy.

How to repair a baby’s broken heart

A rare disorder that prevents some babies from getting enough oxygen to their organs can be repaired through a series of three intricate surgeries. This article and graphic explain the process behind correcting single-ventricle defects, also known as SVDs.This disorder happens when one of the heart's lower chambers doesn't work correctly, resulting in deoxygenated and oxygenated blood circulating the body rather than just the latter.

See this diverse list of vector-borne diseases

Human illnesses caused by parasites, viruses, and bacteria, and transmitted by a living organism—often small, bloodsucking ones like mosquitoes, ticks, and sandflies—are known as vector-borne diseases. That carrier is called a vector. These diseases disproportionately affect the poorest populations in tropical and subtropical areas.

America's top causes of death are heart disease, cancer, accidents, and stroke

Heart disease killed more than 680,000 people in 2023 and cancer killed around 613,000 people that year. Both causes of death are far above the next leading cause of death—accidents, which numbered around 223,000. Provisional data for 2024 indicates the leading causes of death remained the same.

Learn about the more than 100 known autoimmune diseases

Explore this resource with summaries and related resources for the dozens of autoimmune diseases defined in the medical literature. Many of these disease write-ups also have interviews with a patient with the disorder—offering a personal take about challenges, advice, and lifestyle effects.

Exercise helps make your arteries more elastic

Regular aerobic exercise releases nitric oxide, a key molecule that relaxes blood vessel walls and improves vascular function. These exercise-induced adaptations make the heart work more efficiently and blood vessels become more elastic, leading to improved circulation and lowered cardiovascular risk.

Is it possible to cure diabetes?

Treatments for diabetes depend on the type of condition a patient has. Gestational diabetes typically goes away after birth, and those with Type 2 diabetes may be able to reverse their condition through diet, exercise, and blood sugar management. Type 1 diabetes has no cure, but can be successfully managed.

There are hundreds of subtypes of cancer, making a universal cure nearly impossible

Cancer is an umbrella term for over 200 different diseases, each with its own subtypes, genetic mutations, and behaviors. This diversity means that a treatment effective for one cancer type or patient may be ineffective for others. Moreover, as tumors grow, their cells accumulate different mutations, creating subclones with unique characteristics.

Arthritis is an umbrella term for various conditions that cause joint pain

Arthritis isn’t one single disease, but rather a range of conditions that all lead back to the same outcome—joint pain. This American Academy of Orthopaedic Surgeons primer is a go-to resource for understanding what arthritis is, the most common types, and various treatment options depending on the underlying cause.

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.

Long-haul COVID: What doctors want patients to know

Long COVID continues to be a medical mystery, but some parts of the puzzle are falling into place. Learn more from intensivist Devang Sanghavi, MD.

What conditions can be treated with stem cells?

Stem cell research is a global enterprise, and much of the work is being done in Europe. This page gives readers a good sense of the medical conditions stem cell researchers in Europe focus on, and the specific research challenges they address. This page also offers links to in-depth information about many of the research projects.

Extreme grief elevates cardiovascular risk and lowers immune system function

A 2014 analysis of cardiovascular risk and bereavement after a lost partner found that grief elevates the risk of stroke and heart attack for the 30 days following death of a partner and the risk then attenuates after that.

Women's health research continues to be underfunded

Health conditions that affect women more than men get less research funding. This interactive collection of graphs details the gendered gap in health research funding. Of the conditions that affect one sex more than another, those that create the...

Card issuers are financial institutions that open credit to customers, while card networks facilitate purchases between merchants and customers

Card issuers give customers credit cards, set rate limits, and collect payments. Card networks, on the other hand, dictate where credit cards can actually be used by managing relationships between the network and merchants. These networks make money on interchange fees, which merchants pay to accept a specific card network at their stores.

What is CAR T-cell therapy?

A four-minute video about CAR T-cell therapy to help answer patients' questions: What is CAR T-cell therapy? How does CAR T-cell therapy work?

Pulsatile tinnitus is when you hear thumping synchronized with your heartbeat

This rare type of tinnitus, which sounds like rhythmic thumping or whooshing, is often linked to blood vessel conditions or high blood pressure. Lowering blood pressure through exercise and food choices can help reduce the severity of this condition.

Do wearables help those with chronic disease?

The integration of wearable technology in healthcare has promised significant benefits for chronic disease management, yet the actual impact remains underexplored. This systematic review published in the Journal of Medical Internet Research...

See Virginia's emergency stats broken down by date, type, and even body part

This dashboard from Virginia's health department provides a detailed look at various aspects of its emergency care services from January 2019 to December 2024, when there were more than 575,000 emergency incidents. More than 40% of its emergency services were devoted to slips and falls.

Learn all about different types of extreme weather

Find out in more detail about different types of extreme weather, from flooding to thunderstorms, from tropical cyclones to sandstorms, and more (w/ helpful videos).

What causes high cholesterol?

Cholesterol is a complex health issue, and for a long time, the American Health Association recommended Americans not eat more than three eggs a week to avoid it. But scientific advancements on the impact of different types of cholesterol revealed eggs aren't so bad. So what is it, and how does it effect us? Dive into the digestive tract here.

See the differences between chickenpox and hand, foot, and mouth

This helpful explainer breaks down the differences between these two contagious, viral diseases, which both present with fevers and sores. It includes photos of the sores that are characteristic of both diseases, showing how they have appeared across different skin tones to better inform people looking for information about their own loved one's symptoms.

The word 'vertigo' derives from the Latin 'vertere,' meaning to turn

Beyond the word's origin, this article makes clear that fuzzy definitions of the disorder make it confusing for patients to describe it.

This real-time tracking of the hantavirus cruise ship outbreak in May 2026 offers a unique glimpse into the global reach of the outbreak and whether the virus sickened passengers and their communities around the world.

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.

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

Venture capital is a form of funding provided to early-stage companies with high growth potential, typically in exchange for an equity (or ownership) stake

US consumers collectively owe more than $1T to credit card companies—almost as much as they owe in auto loans.

See images of medical cases of firework injuries shared on this 'Instagram for doctors.' (Warning: Graphic content)

Explore the animals that populate the depths of the ocean, from fish and coral in the first few hundred feet, all the way down to the bottom of the Mariana Trench.

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

Doctors differentiate between a phobia and fear by asking patients whether their fear interferes with their day-to-day activities.

Hurricanes, which rely on air consistently spinning in the same direction, cannot cross the equator because air curves in opposite directions north and south of it.

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

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.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in casualties, forces mobilized, and displacement of civilians.

Corals are themselves not coral reefs—the term refers to the tiny marine invertebrates that build the rigid reef.

Poison ivy's rash-causing compound is found in the plant's roots, stem, and leaves—so coming into contact with any part of the plant can lead to rashes for the 85% of people who are allergic to it.

Memecoins are a type of cryptocurrency—a form of digital currency with a wide variety of uses—created around popular 'memes,' or viral internet jokes.

Visualize the path of every solar eclipse from 1900 to 2099 and see what each looks like when observed from different locations on Earth.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

The Dracula character, now seen as the vampire archetype, was inspired by a seafood-induced nightmare its creator experienced.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

The rivalry between Alexander Hamilton and Thomas Jefferson centered on federalism—the question of how much power the federal government should hold relative to the states.

44% of Americans say they pray at least once a day—discover how your state's religiosity stacks up against the rest of the country.

A century of Billboard issues documenting the evolution of popular music.