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

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.

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.

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.

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.

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.

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.

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.

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.

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 CAR-T therapy has become one of the main focus areas for autoimmune diseases

The therapy, originally targeting cancer, involves taking a patient's own T cells, genetically reprogramming them to recognize and attack a specific target and then infusing them back into patients. For autoimmune diseases, the therapy instead programs them to target immune cells that are causing problems, restoring immune system tolerance.

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.

Rheumatoid arthritis occurs when the immune system attacks cells within joints

Rheumatoid arthritis is a specific type of arthritis that occurs when the body's immune system attacks normal cells within the connective tissues of the joint and degrades them. This sets off a painful cycle of inflammation and joint destruction that often requires lifelong medication to control.

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.

Multiple sclerosis means 'many scars'

That's a reference to the scarring or lesions that occur in the brain, spinal cord, and elsewhere whenever the immune system has a flare-up. The immune system attacks the myelin because it incorrectly responds as if it's a threat, damaging the body's ability to transmit electrical signals effectively from areas of the body to the brain.

Lupus, an autoimmune disease with varied symptoms, was named for wolf bite-like lesions

The 13th-century physician behind the name (lupus is Latin for wolf) named it after a patient he saw who had facial lesions that looked to him like a wolf's bite. Other common symptoms of the disease include extreme fatigue, painful and swollen joints, fevers, and light sensitivity.

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.

Measles attacks the body’s immune system, leaving it vulnerable to secondary complications

A measles infection begins in the lungs, where it hijacks cells known as macrophages and begins to replicate itself. It then uses a Trojan horse method to enter the lymph nodes, where it attacks vulnerable T and B cells. Symptoms include fever and rashes.

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.

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

A vaccine against Epstein-Barr virus, researchers hypothesize, could potentially prevent MS

As many as a quarter of MS patients have antibodies in their blood that bind to both a central protein in Epstein-Barr virus and a protein made in the brain and spinal cord that—when attacked—leads to a breakdown of protective nerve fiber insulation. This suggests the immune system's primed to attack the nervous system after mounting a defense against Epstein-Barr.

Scleroderma, which causes skin to harden and scar, has no FDA-approved treatment

It's an autoimmune disease that disproportionately causes worse complications in African American people for unknown reasons. It causes the body to overproduce collagen after the immune system attacks the body's own connective tissue, leading to excess collagen deposits and restricted blood circulation as small blood vessels are damaged. It can damage various organs, including the lungs.

Transplanted organs can be rejected by the body immediately, months after transplant, or slowly over years

Organ rejection remains a huge challenge for organ transplant recipients. Rejection occurs when a recipient's immune system identifies a transplanted organ as foreign and attacks it. Recipient-donor screening processes try to match antigens to help reduce this risk.

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

How ALS (Lou Gehrig’s Disease) might work, and what scientists are learning about it

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder that affects the nerve cells (neurons) controlling muscle movement. As the motor neurons degenerate, they stop sending signals to the muscles, causing progressive muscle weakness and, eventually, death. This three-minute animation focuses on the mechanisms within the motor neurons that cause them to degenerate. By understanding these mechanisms, researchers hope to one day find a cure for ALS.

Cellular aging and deterioration leads to tissue (and overall) aging

Cells are the building blocks of life, forming tissues and organs that keep our bodies working. As we age, cellular changes have progressive consequences on both the structure and function of our organs. This article examines this complex relationship as it relates to the incremental changes associated with aging.

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.

Cancer is runaway growth of abnormal, mutated cells

Cancer cells have mutations in their DNA that allow uncontrolled growth and division, dodge usual mechanisms of cell death, and can often spread throughout the body. This is, in part, why the disease is so difficult to treat, with a wide variety of mechanisms and types that poses unique challenges.

Watch what the Ebola virus does inside our cells and organs in order to spread and survive.

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

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.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

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

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Poison ivy's characteristic rash is caused by an allergic response to an oily compound in the plant called urushiol.

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.

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.

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

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

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

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 concept of phantom limbs, the perception that amputated limbs are still present, dates back to a French military surgeon in the 16th century.

Firework or sparkler burns, even if they cover a relatively small area of skin, can significantly affect our range of motion.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

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.

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