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

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.)

The gut microbiome may play a major role in autoimmune disease and symptom flare-ups

Certain unhealthy foods can promote gut bacterial growth and inflammation in the lining of the gut, potentially disrupting its lining—leading to a leaky gut that may allow pathogens to dribble out into the bloodstream, fueling further inflammation that can both cause disease flare-ups and set the stage for future disease development.

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

Autoantibodies—which attack the body—may be detectable in the body years before a patient develops symptoms, but some people may have detectable levels yet never go on to develop an autoimmune disease. This video discusses this and other unsolved mysteries with autoimmune disease.

Modern conveniences may be contributing to allergy increases

A combination of genetics and how the environment changes our genes are likely contributing to the rise in allergies. But daily conveniences, such as dishwashers and packaged baby food, also change the level of bacterial exposures in early life, with potential implications for allergy development, experts from Mount Sinai Health System state in this video discussion.

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.

Why are women more likely to suffer autoimmune diseases than men?

A majority of Americans with autoimmune diseases have more than one X chromosome, a typical marker of the female biological sex, according to a study published in February of 2024. During fetal development, cells side with one X chromosome over the other, preventing the overproduction of X-chromosome-specific proteins and shutting down the twin chromosome. This article explores how this X-chromosome inactivation can lead to autoimmune disorders by generating antibodies to the body's own tissues.

Women typically have more robust immune responses than men

This difference helps women better combat infectious diseases, but this more turbo-charged response may also make women more vulnerable to autoimmune diseases by potentially priming their immune systems to overreact to their own cells and tissues and label them as invaders that must be destroyed. Roughly 80% of American women have autoimmune conditions.

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.

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.

Researchers are investigating how altering the gut microbiome may influence the development of rheumatoid arthritis, which is an autoimmune disease.

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.

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).

Risk factors linked with ASD include older parents, preterm births, and toxic prenatal exposures

Though researchers agree that there is a strong genetic component to ASD development, certain environmental factors heighten that risk, with studies suggesting older parents, premature birth, maternal obesity, and air pollution exposure in utero all elevate risks of ASD development. There is no connection between receiving vaccines and ASD development.

Why some people have allergies

Why do some people have allergies while others don’t? One theory suggests allergies are a relic of our evolutionary past. Our immune system, once primed to fight parasites, now mistakes harmless substances for threats.

Seasonal allergies don't always show up in childhood

The human immune system may become sensitized to pollen and develop an allergic reaction to it after prolonged exposure. Other triggers for new seasonal allergies may include exposure to new environments and changing climate conditions that affect allergy season length and conditions for various pollens.

Environmental conditions, shifting immunity, and viral strain could help explain 2025 spike

The surge in HFMD in the summer and early fall of 2025 in the mid-Atlantic could be the result of a confluence of factors, including a more virulent strain of disease-causing virus, good environmental conditions for the virus to spread—hot, humd—and a potential immunity gap among kids due to milder HFMD outbreaks the previous year.

Adults are developing food allergies that they didn’t have as children

Research published in 2019 found that almost half of 40,000 surveyed adults with food allergies developed a new food allergy as adults, underscoring that our immune systems may newly misclassify substances later in life.

How one autoimmune disease patient is questing for inflammation cures

This article's writer, who has Hashimoto's Disease and characteristic symptoms from her body attacking her thyroid—like exhaustion, hair loss, and brain fog—shares big take-aways from an anti-inflammatory retreat in Italy. The writer suggests that a holistic approach to eating, sleeping, and stress management, are the only sustainable ways to lower inflammation.

Lack of Vitamin D seems to be one major factor fueling MS risk

Researchers believe that a combination of factors can elevate MS risk, including a lack of vitamin D exposure in different locales, genetic history, cigarette smoke exposure, and Epstein-Barr virus infection.

Microplastics are infiltrating the human body with unclear but concerning effects

Scientists have linked microplastics to immune system damage, hormone disruption, inflammatory diseases, and even cancer—yet most of their health impacts remain unknown due to limited research. Studies suggest we ingest about a credit card's worth of plastic weekly.

Many patients with psoriasis develop other autoimmune diseases, too

A small study published in 2024 found that nearly three-quarters of patients with psoriasis—a condition in which the body attacks healthy skin cells—also developed autoimmune disorders including thyroid diseases, connective tissue diseases, and more, suggesting such connections between these autoimmune disorders warrant further exploration.

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.

Gut microbiome rewrites may help reduce allergies

Researchers are investigating different strategies to determine if one day they could give people a combination of gut microbes to set them up for fewer allergies. In animal research, scientists have already prevented severe allergic responses in allergy-prone mice—supplying them with gut microbes from healthy, non-allergic human babies.

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.

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.

Embracing poor hygiene in early life won't stave off allergies

The hygiene hypothesis, first proposed in 1989 by British immunologist David Strachan, suggests that early life exposure to microbes—like those from farm dust or pets—properly trains our immune systems to respond to threats. But sometimes the idea is misinterpreted: It doesn’t mean that poor hygiene—like failing to wash hands–will help ward off allergies; that type of behavior leads to infections and won’t help with allergy prevention.

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.

Cancer rates are on the rise among GenXers and Millennials

Cancer rates are rising among Gen X and Millennials, with more cancer diagnoses being made in their 30s and 40s than previous generations. Factors such as prenatal exposures, environmental toxins, and lifestyle choices may contribute to this trend. Memorial Sloan Kettering Cancer Center's experts discuss these issues, exploring how these insights could reshape cancer risk understanding.

Climate shifts are projected to cause more cases of food poisoning

Research published in 2024 suggests that with more severe heatwaves and natural disasters, scientists expect there to be a rise in foodborne disease, especially in Africa and Asia. Already, there are an estimated 600 million food poisoning cases and 420,000 deaths annually. Diarrhea is the most common cause of those deaths.

Inflammaging appears to differ across global populations

Chronic, low-grade inflammation linked to aging is a byproduct of our industrialized lifestyles, according to recent research. The work compared two industrialized populations with two Indigenous, non-industrialized populations in Bolivia and Malaysia, and found that inflammation levels in the Indigenous groups—unlike the industrialized ones—did not seem to differ by age.

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

Climate change is influencing the spread of disease

Rising temperatures and water levels are forcing animals and pathogens beyond their typical boundaries. This article and its data visualizations explore the proliferation of climate-driven diseases.

Inflammaging is chronic low-level inflammation as we age, and it may be a key disease driver

The term refers to the idea that largely invisible but consistent low-level inflammation as humans age fuels chronic diseases and cellular aging. Inflammaging, this article says, is due to lifestyle factors like poor sleep, low levels of activity, and poor diet, acting in concert to cause cellular damage and trigger inflammation.

The word allergy is partly derived from the Greek word 'allos' for 'other'

For people with allergies, their immune systems recognize substances as a harmful "other"—cuing an inflammatory response. This podcast explores allergy details and related topics, including how scientists are interested in if the same allergic response mechanisms could underpin other health issues, including severe, painful symptoms around the time of menstrual cycles. Since estrogen acts on white blood cells called mast cells, which leads to the release of histamines—similar to what happens during allergic responses—an understudied question is whether the same process is fueling some of the uncomfortable symptoms around menstruation. An allergist guest notes this raises questions about if antihistamine medications like Pepsid might alleviate them, something that hasn't yet been explored in clinical trials.

Trillions of bacteria, viruses, fungi, protists, and archaea live in our guts, producing a wide range of molecules, hormones, and more—underscoring the immune system's pivotal role in the microbiota-gut-brain axis.

There's no specific anti-inflammatory diet, but certain foods increase the chance of inflammation

Research suggests humans can reduce inflammation by limiting foods that are already known to be unhealthy for the human body—because they alter gut bacteria and stress the immune system—such as highly-processed foods, deep fried foods, sugary drinks, trans fats, red meats, and foods made with white flour. Foods that help the body include fatty fish such as salmon, legumes, fruits, and vegetables.

Inhalers, antihistamines, immunotherapy, and more have made allergies a multimillion-dollar market

Market research suggests that the allergies market will continue to grow in the years ahead as the number of allergy diagnoses increases, identifying new patients. Areas of growth include the increasing interest in immunotherapies designed to retrain the immune system through regular exposure to potential allergens via injections and under-the-tongue medical formulations, among other approaches.

Chronic inflammation can cause cellular damage and could lead to cancer

Over time, this cellular defense system can inadvertently damage cells and tissues when it's in this heightened alarm mode over a prolonged period. This occurs because, when immune cells are sent somewhere without a true target, they may attack healthy cells and tissues.

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 to think yourself into health

Can the right thoughts lead to a stronger immune system? Neuroimmunologists like Hai Qi study how drugs targeting the brain, as well as thought exercises, can prompt stronger immune responses to infection. This six-minute video investigates the radical claims.

Addressing lifestyle factors, which influence inflammation, can cure some chronic diseases

In this video, a physician claims that he reversed a patient's Type 2 diabetes in six weeks by addressing inflammation drivers such as diet. More broadly, he argues that society needs to better consider and address numerous disease factors that are modulated by inflammation, such as stress, sleep, diet, and movement.

How the microbiome affects your health

The gut microbiome is so influential to overall human health that some researchers consider it a separate organ. Its conditions, influenced by environmental and lifestyle factors such as medication and exercise, contribute to immunity, metabolism, inflammation, medical treatment efficacy, brain development and function, and the development of disorders and diseases, including asthma, depression, inflammatory bowel disease, and Alzheimer's.

Can the gut microbiome drive addiction?

New research suggests an imbalance of gut microorganisms may influence the likelihood of addiction and addictive behaviors by increasing the severity of withdrawal symptoms, triggering brain inflammation in regions of impulse control, and more.

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.

An interactive dive into the immune system

Our bodies are equipped with an incredible system able to fight off invasive pathogens to protect us from illness. The complicated system includes lymph nodes, the spleen, bone marrow, and even the tonsils. But this same system can turn against itself, a condition known as autoimmune disorders. Follow along with this thorough, engaging explainer on the human body's defense system.

Health problems are being misdiagnosed as perimenopause symptoms

Symptoms of menopause and perimenopause (the premenopause period) can be varied enough that clinicians dismiss them in patients in their mid-30s and onward as just a symptom of hormone level change. In this story, a woman's itching was dismissed as a hormonal change, but after two years and 11 separate doctor consultations, was diagnosed as cancer. (Some users may experience a paywall.)

More than 20 mosquito-borne and tick-borne diseases are found in the US

Children, older adults, and people with compromised immune systems are at particular risk of poorer health outcomes from these diseases. But dog owners and outdoor enthusiasts are among those at particular risk of contracting these illnesses, which include Lyme disease, Zika, and the condition Alpha-gal Syndrome.

Research shows that microplastics and nanoplastics can accumulate in major arteries, and patients with these deposits are significantly more likely to suffer heart attacks, strokes, or death.

Rapid environmental changes are exacerbating natural extinction processes

Human activities behind climate change, habitat destruction, pollution, and overhunting have resulted in extinction rates up to 1,000 times greater than normal, triggering massive biodiversity loss. This has led scientists to refer to the current geological age as the Anthropocene era, in which humans are the dominant force shaping nature.

Allergies occur when our immune system mistakenly considers a substance a threat

Immunoglobulin E antibodies, or IgE antibodies, may bind to an allergen, effectively labeling it as a threat. That triggers a cascade of actions in the body, including the release of histamine, which causes the characteristic itching and hives of allergies. Sometimes a cooked version of an allergen—like a cooked carrot—may look different enough from its raw form to the immune system that antibodies ignore it, and no allergic response takes place.