Autoimmune Diseases: Why They Mostly Affect Women
What if you had painful joints, a rash that will not go away, and unexpected fatigue when you wake up? You see a doctor, but the symptoms do not suggest any one disease. Your immune system is attacking your body, and more tests are performed months later.
This is how some autoimmune diseases begin. They may impact the skin, joints, brain, nerves, digestive system, thyroid, and different organs. Some result in mild symptoms; others can result in serious damage.
A large proportion of this disease burden falls on women. According to a 2026 report by the Yale School of Medicine, over 80% of Americans who suffer from autoimmune conditions are women. Researchers are still working on the explanation for the difference.
New research will also investigate treatments that could alter the way in which doctors treat these conditions. The following information will help you understand autoimmune diseases, what symptoms to look for, what causes them, and potential treatments.
What are autoimmune diseases?
The immune system protects the body from harmful germs and other threats. It uses special cells and proteins to identify and attack foreign invaders.
But sometimes, the system makes a mistake. It treats healthy cells as threats and attacks them. This causes inflammation and damage to the body's own tissues.
There are more than 80 recognized autoimmune diseases. Each affects the body differently.
For example, rheumatoid arthritis attacks the joints and can cause pain and swelling. Lupus can affect the skin, kidneys, heart, lungs, and joints. Multiple sclerosis damages the protective covering around nerves in the brain and spinal cord.
Other conditions affect the thyroid, digestive system, muscles, or hair follicles. This explains why autoimmune diseases can cause such different symptoms.
Why autoimmune diseases affect more women
Women are more likely than men to develop many autoimmune conditions. However, the difference varies by disease, and men can also develop serious forms.
Researchers believe several factors may help explain the gap.
Hormones such as estrogen may affect how the immune system works. Women also have two X chromosomes, which carry many genes involved in immune activity. Scientists are studying whether differences in how cells control these chromosomes affect disease risk.
Genes and environmental factors also matter. Infections, smoking, and some chemical exposures may contribute to certain conditions in people who are already at risk.
These factors do not mean that every woman will develop an autoimmune disease. They help explain why some people are more vulnerable than others.
What symptoms should you watch for?
Symptoms depend on the part of the body under attack. Some people experience several problems at once.
Common warning signs include:
- Ongoing tiredness that does not improve with rest
- Painful, swollen, or stiff joints
- Repeated skin rashes
- Muscle weakness
- Hair loss in patches
- Unexplained fever
- Digestive problems, including diarrhea and stomach pain
- Numbness, tingling, or problems with balance
Some autoimmune diseases also cause symptoms that come and go. A person may feel well for weeks before experiencing a sudden worsening called a flare.
For example, someone with lupus may have joint pain and fatigue one month, then develop a skin rash during another flare. A person with multiple sclerosis may experience vision problems, weakness, or difficulty walking.
These symptoms do not automatically mean someone has an autoimmune disease. Many other conditions can cause similar problems.
Why diagnosis can take so long
Autoimmune diseases can be difficult to diagnose because their symptoms often resemble other illnesses.
Doctors usually review a patient's symptoms, medical history, and physical examination. They may also request blood tests to look for inflammation or antibodies that attack healthy tissues.
However, a positive antibody test does not always mean someone has an autoimmune disease. Doctors must consider the results alongside symptoms and other findings.
Some patients need imaging scans, organ tests, or specialist assessments. A person with suspected lupus, for example, may need kidney tests to check for inflammation or damage.
This process can take time. Keeping a record of symptoms, flare-ups, and possible triggers can help patients explain what they experience during appointments.
Can infections trigger autoimmune diseases?
Researchers believe some infections may help start autoimmune activity in people with certain genetic risks.
One example is the Epstein-Barr virus (EBV). Most people become infected during their lives, and the virus can remain inactive in the body.
A 2025 study published in Science Translational Medicine found that EBV can change the behavior of certain immune cells in people with lupus. These cells may then help activate other immune cells that attack healthy tissues.
The finding offers a possible explanation for how the virus contributes to lupus. It does not mean that everyone infected with EBV will develop the disease.
Researchers are also studying how infections and other environmental factors may contribute to multiple sclerosis and other autoimmune conditions.
New treatments may help reset the immune system.
Most current treatments aim to reduce inflammation, control symptoms, and prevent organ damage. Doctors may use steroids, immune-suppressing medicines, or drugs that target specific parts of the immune system.
But researchers are now exploring treatments that could change the immune response more deeply.
One approach is CAR-T cell therapy. It modifies a patient's immune cells to target specific cells involved in disease. Scientists first developed this treatment for certain cancers, but they are now testing it for autoimmune conditions.
A phase 1/2 trial published in Nature Medicine in January 2026 studied 24 people with treatment-resistant lupus, systemic sclerosis, or inflammatory muscle diseases. After treatment, 22 participants met the study's defined response goals at 24 weeks.
These early results are encouraging, but the trial was small and had a short follow-up period. CAR-T therapy can also cause serious side effects and is not a routine treatment for autoimmune diseases.
Another example is teplizumab, a medicine approved to delay the progression of early-stage type 1 diabetes in eligible patients. It slows the immune attack on insulin-producing cells, but it does not prevent or cure the disease.
Bottom line
Autoimmune diseases can affect almost any part of the body. Women develop many of these conditions more often than men, although researchers are still investigating why.
Early diagnosis and treatment can help control symptoms and reduce organ damage. New therapies, including CAR-T treatment, offer hope, but most remain under study.
Anyone with persistent, unexplained symptoms should seek medical advice rather than assume an autoimmune condition causes them.
Frequently Asked Questions
Can autoimmune diseases affect men?
Yes. Women are more likely to develop many autoimmune conditions, but men can also develop lupus, rheumatoid arthritis, multiple sclerosis, and other diseases.
Can autoimmune diseases be cured?
Most autoimmune diseases do not yet have a cure. However, medicines can control symptoms, reduce inflammation, and help prevent damage.
Are autoimmune diseases inherited?
Some people inherit genes that increase their risk. However, genes alone do not explain every case. Environmental factors and infections may also play a role.
