Autoimmune diseases occur when the immune system attacks the body's own tissues and include more than 100 disorders that together affect tens of millions worldwide. They are most common in women (about 4 of 5 cases), are often hard to diagnose because symptoms overlap or are vague, and can be unpredictable. New research and clinical trials aim to reprogram or delay harmful immune responses, offering hope beyond symptom control, but treatment often remains lifelong and costly.
Autoimmune Diseases Explained: Why They Mostly Affect Women and What’s Changing in Treatment
Autoimmune diseases occur when the immune system attacks the body's own tissues and include more than 100 disorders that together affect tens of millions worldwide. They are most common in women (about 4 of 5 cases), are often hard to diagnose because symptoms overlap or are vague, and can be unpredictable. New research and clinical trials aim to reprogram or delay harmful immune responses, offering hope beyond symptom control, but treatment often remains lifelong and costly.
02:33, 07.11.2025Health
Our immune system usually protects us from germs and cancer, but sometimes it misfires and attacks the body's own cells and tissues. Those conditions are called autoimmune diseases — a diverse group of more than 100 disorders that can affect nearly any organ and together impact tens of millions of people worldwide.
Although autoimmune diseases are most common in women, they can develop in anyone at any age. Incidence appears to be rising, and new research is shifting hope from symptom control toward therapies that may reprogram or delay a wayward immune response.
“This is probably the most exciting time that we’ve ever had to be in autoimmunity,” said Dr. Amit Saxena, a rheumatologist at NYU Langone Health.
What are autoimmune diseases?
Autoimmune diseases are chronic conditions that range from mild to life-threatening. More than 100 distinct disorders exist, often named for the tissues they attack: rheumatoid and psoriatic arthritis target joints; Sjögren’s disease commonly causes dry eyes and mouth; myositis and myasthenia gravis weaken muscles by different mechanisms; and lupus can produce a butterfly-shaped facial rash as well as inflammation of kidneys, lungs and heart.
These illnesses can be unpredictable. People who seem stable may suddenly experience a flare of symptoms with little warning.
Why diagnosis is often difficult
Many autoimmune conditions begin with vague, intermittent symptoms that resemble other disorders, and several diseases share overlapping signs. Diagnosis typically relies on a combination of clinical symptoms, blood tests that may detect antibodies targeting healthy tissue, and ruling out other causes. For some patients it can take years and consultations with multiple specialists before the pieces fit together. Efforts are underway to speed recognition—for example, updated guidelines and clinician education aim to streamline diagnosis of multiple sclerosis.
How the immune system goes awry
The immune system is a complex network of sentinels, attack cells and regulators that normally distinguish foreign invaders from the body's own cells — a feature called tolerance. Autoimmunity arises when tolerance fails: misdirected immune cells or antibodies persist, or regulatory signals do not shut down inflammation after an infection or injury, allowing damage to develop over time.
Triggers and early events
Most adult-onset autoimmune diseases are not caused by a single mutated gene. Rather, a combination of genetic variants that influence immune function creates susceptibility, and an environmental trigger — such as an infection, smoking or pollution — can set the disease in motion. Epstein-Barr virus, for example, has been linked to multiple sclerosis. Researchers are also examining early molecular events; overactive neutrophils (a type of white blood cell) appear to play a role in conditions like lupus and rheumatoid arthritis.
Why women are at higher risk
About four of five people with autoimmune diseases are women, many of them young. Sex hormones likely contribute, and researchers are investigating how X chromosome biology — females have two X chromosomes while males have one X and one Y — might increase vulnerability when X-inactivation is imperfect. Men are not immune: VEXAS syndrome, identified in 2020, primarily affects men over 50 and can cause severe systemic inflammation along with blood clots and respiratory symptoms. Risk also varies by population; for example, lupus is more common among Black and Hispanic women, while people of Northern European descent have a higher risk of multiple sclerosis.
Treatment: progress and remaining challenges
Treatment is generally lifelong and can be costly. Historically, care relied on high-dose steroids and broad immunosuppressants, which control inflammation but raise risks of infections and certain cancers. In recent years, targeted therapies that block specific molecules or pathways have reduced side effects for many patients, and dozens of clinical trials are testing approaches to reset or retrain the immune system — with early promise in diseases such as lupus and myositis. Some interventions can even delay the onset of disease in high-risk people, such as a drug that postpones symptoms in some who later develop type 1 diabetes.
Despite advances, choosing the right therapy often remains a process of trial and error. Better biomarkers and more personalized approaches are active areas of research and are key to improving outcomes and reducing long-term costs and harms.
Note: This article summarizes current research and clinical trends. Patients should consult their physicians for personalized medical advice.