Autoimmune diseases affect between 5% and 10% of people worldwide, but their causes remain unknown

How autoimmune diseases, which attack your own tissues and cells, work in the body

These diseases remain some of medicine's thorniest problems because the immune system can mistakenly attack almost any tissue in the body, resulting in myriad diseases, including lupus (numerous tissues affected), Hashimoto's (thyroid), and MS (the nervous system).

More than 5 million Americans have more than one autoimmune disease

Overall, about 4.6% of the US population—15 million people—have an autoimmune condition. Some common examples include rheumatoid arthritis, psoriasis, type 1 diabetes, Grave's disease, and autoimmune thyroiditis.

Autoimmune disease prevalence and incidence are on the rise—but no one knows why

Researchers theorize that environmental factors, including shifts to less healthy diets, air pollution, infections, stress, climate change, and exposures to xenobiotics—substances like pesticides, plastics, and toxins that incite immune responses—may all be fueling epigenetic changes to our bodies that make people's immune responses go awry.

Autoimmune disorders are one of the top 10 killers of young and middle-aged women

Studies in the US and the UK, though conducted decades ago, have underscored that autoimmune diseases, when grouped together, are a top killer of women.

Almost 80% of people diagnosed with autoimmune diseases are women

Yet it's still unanswered what may account for that difference. To better understand this disparity researchers are exploring factors including hormonal changes that occur around puberty, pregnancy, and menopause, as well as gut microbe differences, and aspects of X-chromosome protein-coding genes. (Some users may encounter a paywall.)

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.

Rheumatoid arthritis affects about 1% of the population

Rheumatoid arthritis is an autoimmune condition leading to breakdown and inflammation of multiple joints throughout the body. This academic article provides an updated deep dive into our current cellular understanding of rheumatoid arthritis, how it is diagnosed, and the variety of medications available for treating this painful condition.

How Nobel Prize-winning research unraveled why the immune system doesn't always attack itself

The 2025 Nobel Prize was awarded to scientists who discovered how immune system soldiers are typically stopped from attacking healthy tissue. The work furthered autoimmune understanding and cancer therapies.

The science of food allergies

Why do certain substances trigger an immune response while others don't? Listen to researchers explain the science in this five-minute video. Food allergies affect around 8% of children and 2% of adults in the US, and—unlike sensitivity or intolerance—they involve the immune system mistaking certain harmless proteins in foods as dangerous invaders, triggering a rapid and sometimes severe defense response.

Autoimmunity is when the body attacks itself, causing inflammation

Inflammation is the body's way of healing itself, and acute inflammation saves our lives when we have injuries or infections. It increases blood flow to the affected areas to bring immune cells to fight off invaders. This often results in short-term swelling, redness, and pain.

Type 1 diabetes is an inherent autoimmune disorder inhibiting insulin production

Diabetes causes the body to attack insulin-producing cells in the pancreas, causing a shortage or lack of insulin. This prevents the body from accessing and storing blood sugar—the brain and muscles' primary energy source. It's unclear what causes Type 1 diabetes, an incurable yet manageable chronic condition as of 2024.

Five to ten percent of Alzheimer's cases are early-onset

Early-onset Alzheimer’s typically emerges around 40 to 50 years of age, with devastating effects. This video follows Brian, diagnosed with the disease at age 54, as he travels the country as an advocate for research and discusses the progressive mental fog of Alzheimer’s.

Twin studies suggest celiac disease is among the more genetically-linked disorders

Genetics appear to play a larger part in this condition's development than many other autoimmune disorders. Research shows a roughly 60-75% genetic probability that if one identical twin has it, the other will too. Celiac triggers a small intestine attack when people eat gluten, a protein commonly found in wheat, barley, and rye.

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

One in 10 adults worldwide has diabetes

As of 2021, diabetes claimed at least 6.7 million lives and continues to kill one person every five seconds. Nearly one in two adults with diabetes don't know they have the condition, which is expected to increase in prevalence from 537 million in 2021, to 783 million in 2045.

GLP-1s are netting interest for treating autoimmune diseases, but are considered experimental

Already used to treat type 2 diabetes, the novel medications are showing some early promise in experimental studies at reducing inflammation and treating autoimmune conditions including rheumatoid arthritis and inflammatory bowel conditions. But researchers caution that side effects are still under investigation—rarely the medication has caused lupus, an autoimmune disease.

MS can damage the brain up to 7 years before symptoms appear

Recent research scouring blood samples from 134 people with MS, both before and after their diagnosis, found that about seven years before these patients were diagnosed, there was a spike in a protein called myelin oligodendrocyte glycoprotein—indicating disease-associated damage to the protective myelin around nerve fibers.

Less than 1% of people globally have schizophrenia, a syndrome strongly linked to genetics

Schizophrenia's causes remain largely unknown, though scientists suggest it's caused by multiple factors. Its symptoms include disruption of thought processes rather than the exhibiting of multiple personalities. This brief video provides an overview of the condition.

Tinnitus estimates vary, but may occur in 10%-15% of the population

This video discusses the mechanisms underlying tinnitus and explores the knowns and unknowns about the condition. Tinnitus most commonly occurs among those with hearing loss, suggesting that cochlear damage may be a factor.

What are 'antibodies'? Read this quick overview

Antibodies are protective proteins produced by your immune system. They attach to antigens (foreign substances) and remove them from your body. Understand this important element of the immune system with this quick overview.

Autism rate increases are mostly among those with milder symptoms, not individuals with severe symptoms

Broader case definitions and better screening are typically now detecting more milder cases of autism rather than individuals who have severe impairments (who could be categorized as having profound autism). Profound autism rates, an autism researcher says in this article, have stayed proportionately steady.

Why don't we all have cancer?

The creation of a single cell produces 120,000 genetic mutations that can lead to cancer. This video investigates how our bodies proofread and autocorrect those mistakes.

Leprosy symptoms may appear 20 years after infection, so contact tracing isn't possible

The standard approach for tracking disease transmission isn't realistic for this disease because symptoms may take decades to manifest. As a result, disease transmission is still not fully understood.

Before vaccines, there was 'variolation': what was it?

Before the technology behind vaccinations was discovered, some keen observers of medicine around the globe noticed how previous infections could impact future ones. Learn about the techniques early physicians used before they had vaccines.

Five key causes of World War I

What caused World War I? The ready answer refers to the assassination of Archduke Franz Ferdinand. But there was more to it than that. This article, accompanied by a short explanatory video, outlines how mutual defense alliances, imperialism, militarism, and nationalism also had a heavy hand in the start of what some considered a "preventable war."

Animal-to-human pathogens constitute 75% of emerging infectious diseases

Zoonotic diseases encompass more than 200 diseases transmitted from animals to humans, wherein humans are usually accidental hosts. Ranging from rabies to HIV to monkeypox, this overview lists some of the most common viral threats.

Learn how monoclonal antibodies, which mimic the body's antibodies, can fight diseases like Ebola.

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

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

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

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

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.

About 12.5% of US adults experience a phobia in their lifetime, a diagnosis that hinges on the intense fear interfering with daily life and persisting for at least six months.

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.

Between 10 million and 50 million people in the US develop rashes from poison ivy, poison sumac, and poison oak each year.

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.

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

About 2,000 US babies are born annually without some portion of their limbs, potentially leading to a lifetime of pricey prosthetics.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

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

The United States is one of only around two dozen countries with a fully federal system of government, in which power is divided between national and state governments.

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

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

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

View the ten deadliest tornadoes in US history.

The Mona Lisa's celebrity status and repeated restorations have obscured what made the painting so revolutionary for its time

English mathematician Ada Lovelace wrote the first computer algorithm a century before computers existed and hypothesized that computing devices would one day be able to compose music—foreseeing the generative AI systems of today.

Salvador Dalí believed he was his own dead brother, who had died nine months before he was born

The first steps to rebuilding your credit score include getting to know exactly what's on your credit report and figuring out how far you are from the '700 club,' or 'good score' range.

In 1963, a basement renovation in Turkey revealed a passageway to a hidden, multilevel underground city that once housed as many as 20,000 people