Why Are Autoimmune Diseases More Common in Women?

Autoimmune diseases are conditions where the immune system mistakenly attacks its own healthy tissues and organs. Heredity, genetics, and environmental triggers are thought to cause these conditions. There are more than 100 different types and up to 75% of those living with these conditions are women and girls.

There are lots of theories about why females are more susceptible to these conditions, but researchers don’t have definitive answers. Keep reading to learn about why autoimmune diseases might affect more females, which ones are most common in women, and the effect they have.

What are Autoimmune Diseases?

A healthy immune system protects the body against viruses, bacteria, and other foreign substances. When the immune system mistakes healthy tissues for diseased ones, it can attack itself. That process is a called autoimmunity—the main feature of autoimmune diseases.

According to the Office on Women’s Health, autoimmune conditions are common and affect more than 23.5 million Americans. These conditions are a leading cause of death and disability.

Autoimmune diseases can attack any part of the body weakening certain body functions, and potentially causing life-threatening complications. Some well-known autoimmune diseases are rheumatoid arthritis (RA), systemic lupus erythematosus (lupus), multiple sclerosis (MS), and Graves’ disease.

Autoimmune diseases are incurable and most require lifelong treatment to keep symptoms managed and to reduce the potential for life-threatening problems.

Initial symptoms of autoimmune diseases tend to be vague, which can make it difficult to get a timely diagnosis. A diagnosis of an autoimmune disorder is usually made with a physical exam, medical history, blood tests, imaging, and other diagnostic testing.

While these conditions can’t be cured, advancements in medicines for treating autoimmune disorders are improving prognosis and patient function. Lifestyle modifications, like stress reduction, a healthy diet, and exercise, can also be helpful in reducing autoimmune flare-ups.

Why Are Women More Often Affected?

There are multiple theories about why women get autoimmune diseases more often than men. Researchers speculate gender differences in immunity, sex hormones, genetic susceptibility, environmental triggers, and stress might play a part in the development of these conditions and the increased risk to women.

Sex Differences in Immunity

Females generally have more responsive and more sensitive immune systems compared to males. Additionally, they naturally have stronger inflammatory responses when their immune systems are triggered.

Under normal circumstances, inflammation would respond to attack the pathogen as quickly as possible and the inflammatory process would end. However, in autoimmune diseases, inflammatory responses will become chronic and eventually lead to significant tissue, organ, and joint damage.

Sex Hormones and Pregnancy

Another possible theory as to why women have a higher risk for autoimmune diseases has to do with hormonal differences. In fact, sex hormones in women can actually amplify an immune system response to infection, eventually leading to the development of an autoimmune disease.

Women and girls experience significant hormonal events throughout their lives—from puberty to pregnancy to menopause. All of these events can heighten immune system responses to levels that, along with other risk factors (genes, environmental, etc.), can trigger the development of an autoimmune disorder.

Research shows the female hormone estrogen can affect the immune system. One study reported in 2018 in the journal Science Signaling found that estrogen hormone secretion could contribute to the development of autoimmune disease in women.

According to a 2020 report in the journal Cureus, pregnancy causes an invasion of hormonal and body changes that may continue up to a year post-pregnancy. These changes—metabolic rates, lipid levels, and weight gain— can trigger autoimmune responses.

In addition, pregnancy will include significant changes to estriol, progesterone, and prolactin hormone levels. In women who have autoimmune diseases, pregnancy can either improve or flare-up (worsen) these conditions.

Other evidence shows that a fetus relies on the mother’s immune system, potentially causing the maternal immune system to suppress itself in order to protect the fetus. A suppressed immune system is another possible trigger for the development of an autoimmune disease, as are hormonal changes in the post-partum period.

There is also evidence that fetal cells may remain and circulate in a women’s body many years after pregnancy. These cells might be involved in the development or worsening of some autoimmune disorders.

Genetic Susceptibility

Some researchers think because women have two X chromosomes, they are genetically predisposed to developing autoimmune diseases. They suspect defects in X chromosomes are related to autoimmunity. And because women have two X chromosomes, their risk for autoimmune diseases could be two or more times higher than for men.

A 2019 study from researchers at the University of California Los Angeles (UCLA) revealed a specific genetic gene in X chromosomes might offer some explanation as to why women and girls are more susceptible to autoimmune conditions like RA and MS.

This gene is known as KDm6a and was found to be more evident in women’s cells. The researchers also found similar evidence in female mice. When the gene was eliminated in the female mice, they had improved symptoms, less inflammation, and less spinal cord damage.

The UCLA research team shared that they found these results to be helpful in explaining why women have a higher risk for most autoimmune diseases. Additionally, they concluded that further research on suppressing the Kdm6a gene could be useful in treating and controlling symptoms of autoimmune disorders.

Environment Triggers

Researchers pay a lot of attention to how environmental factors play a role in triggering autoimmune disease. Most believe exposure to different types of external toxins, including environmental pollutants and certain medications, might trigger autoimmune responses.

Researchers have found a female gender bias for some exposures like the connection between cosmetics and the increased risk for lupus or RA in women. Although the research is limited, researchers continue to look at products women use in greater frequency, such as hair dyes and makeup, to determine what specific environmental triggers pose the highest risk.

Stress

Stress can affect your body’s immune system. In fact, autoimmunity can develop when stress alters the ability of cortisol to regulate inflammation. A study reported in 2019 in the Journal of the Medical Association revealed that stress from traumatic and stressful life events could increase a person’s risk for developing an autoimmune disease.

Women process stressors differently than men and their bodies respond differently when they encounter stressful situations. A study reported in 2017 in the Journal of Neuroscience Research found that while men and women reported similar levels of stress in stressful situations, men had more robust responses whereas women displayed smaller, weaker responses.

If a person is experiencing chronic stress, a reduced cortisol response cannot protect against inflammation. And abnormal and chronic inflammatory responses may eventually lead to autoimmune diseases, especially in people who have weaker responses to stress. 

Autoimmune Conditions Most Common in Women

Some of the most common autoimmune diseases primarily affect women. Each of these is unique in its processes, but most share common symptoms, including fatigue, pain, and low-grade fevers.

Hashimoto's Thyroiditis

Hashimoto's thyroiditis is an autoimmune disease that causes hypothyroidism (underactive thyroid). With Hashimoto’s, the immune system attacks and damages the thyroid, the small, butterfly-shared gland on the front of your neck.

A damaged thyroid cannot make enough thyroid hormone. Thyroid hormones are important to your body because they control how it uses energy to perform nearly every single body function. Without enough thyroid, your body functions slow down.

Hashimoto’s disease is up to 8 times more common in women than men. While the condition can affect teens and young women, most women are diagnosed between the ages of 40 and 60. There is a heredity component to Hashimoto’s disease, and you are more likely to develop the condition if someone else in your family has it.

Graves’ Disease

Graves’ disease is an autoimmune disease that causes hyperthyroidism (overactive thyroid). With Graves’, the immune system attacks the thyroid and causes it to produce more hormones than the body needs. 

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Graves’ disease affects 7 to 8 times more women than men. Much like Hashimoto’s, your chances of developing Graves’ are much higher if you have a family member with the disease.

Rheumatoid Arthritis

RA is an autoimmune disease that occurs when the body’s immune system attacks the joints. RA affects the lining of the joints causing painful inflammation that eventually leads to bone erosion and joint deformity. RA can also cause damage to multiple body systems and affect the skin, heart, eyes, and blood vessels.

More women than men have RA. Worldwide prevalence studies show RA affects women 3 times more often than it does men.

Systemic Lupus Erythematosus (Lupus)

Lupus occurs when the immune system attacks joints and healthy tissues throughout the body. It can be difficult to diagnose because the signs and symptoms of lupus are found in other autoimmune disorders. Lupus is known for sometimes causing a facial rash on the cheeks that appears like the wings of a butterfly.

According to a 2020 report in the journal Mayo Clinic Proceedings, lupus affects 9 times more women than it does men. The average age for diagnosis is around age 35, and most women are diagnosed at some point during their reproductive years.

Myasthenia Gravis

Myasthenia gravis (MG) is an autoimmune disorder where the body attacks its own neuromuscular connections. These attacks disrupt communications between the nerves and muscles, eventually leading to muscle weakness. MG affects the skeletal muscles, responsible for moving and breathing.

According to the Myasthenia Gravis Foundation of America, MG affects more women under the age of 40. However, it becomes more common in men after age 60.

Multiple Sclerosis

MS is a disabling disease of the brain and spinal cord where the immune system attacks the protective coverings of nerve fibers. These attacks interrupt connections from the brain to the rest of the body, leading to permanent damage to nerves.

According to the National Multiple Sclerosis Society, MS is 3 times more common in women than men. This is likely due to sex hormones that promote a higher susceptibility to women in developing the condition.

Signs and symptoms of MS will depend on which nerves are affected. Some people will lose their ability to walk while others can experience disease remission (no signs and symptoms of disease). MS has no cure, but treatment can slow down the disease and its effects.

Disease Severity and Treatment

Studies have looked at the severity of autoimmune diseases in women compared to men. What they have found is that gender plays a part in the severity of autoimmune diseases and degrees of disability. But this effect will vary based on the autoimmune disease that is causing symptoms.

For example, women with RA usually have more aggressive disease symptoms and higher incidences of disability. Researchers sometimes point to lower muscular strength, reduced stress responses, and the effects of certain sex hormones to explain this.

Another example comes from a 2014 review on gender differences in autoimmune diseases that finds female patients with lupus are more likely to “suffer from urinary tract infections, hypothyroidism, depression, esophageal reflux, asthma, and fibromyalgia." Menopause also seems to worsen lupus symptoms, especially in women who are post-menopausal. 

Autoimmune diseases aren’t treated based on gender. This is because healthcare providers know that these conditions are subjective. This means while you might experience similar symptoms to others with the condition, you can still experience a higher disease burden with more pain, stiffness, fatigue, and disability.

Healthcare providers do know that women will have different disease experiences than men. Therefore, they will implement treatment based on factors specific to you, including how the disease is affecting your life and any risk factors you have for co-morbid conditions connected to a specific autoimmune disease.

A Word From Verywell

Autoimmune diseases are lifelong conditions that cannot be cured. This means you will need to manage and treat your autoimmune disease for the rest of your life. And regardless of your gender, your disease experience will be different than everyone else with the condition.

But no matter what disease symptoms you experience, it is vital to work with your healthcare provider to find a successful treatment plan that maximizes your outlook and allows for you to have a good quality of life. Ask your practitioner what you can do to keep your symptoms managed and how to avoid the long-term consequences of your specific autoimmune disorder.