Dozens of Autoimmune Disorders Share a Few Common Causes

The body's immune system safeguards it against disease and infection—foreign bodies. Autoimmunity happens when this defensive network mistakenly perceives benign cells and tissues in the body as foreign invaders and launches an attack against them.

Medical science knows of more than 100 types of autoimmune disorders. Each can produce myriad symptoms and complications that substantially impact a person's overall health and well-being. These conditions affect approximately 50 million Americans.

Many autoimmune disorders originate in one area, such as a single joint or organ, but affect multiple parts of the body. For example, Hashimoto's thyroiditis starts when the immune system attacks the thyroid gland, but the disease's impact on the endocrine system can have broad consequences for everything from metabolism to cognition to menstruation.

Specifics vary from one illness to another, but many autoimmune conditions tend to get worse and impact more facets of health over time. Mental health issues such as depression and anxiety commonly co-occur with physical challenges in people with autoimmunity.

'Other risk factors associated with autoimmune conditions include smoking, periodontal disease, exposure to toxins, an inflammatory diet and certain medications. Existing autoimmune conditions increase the risk of subsequent disorders.'

Many people with autoimmunity experience sexual health implications, too. Shared challenges across disorders include low libido, diminished self-confidence and difficulties with erections and orgasm. Some conditions produce additional sexual side effects, such as infertility or decreased sensation in the genitals.

Multiple sclerosis, for example, can cause genital numbing, and Sjögren's syndrome is associated with vaginal dryness.

For people of reproductive capacity, inheritance may also be a concern, as autoimmunity is thought to have a genetic component. About 20 percent of people with autoimmune disorders have a family history of autoimmunity.

Risks, causes and triggers

The reason autoimmunity occurs is unknown and may vary from one specific condition to another. However, genetics, environmental factors, chronic inflammation and hormones may contribute.

Autoimmune conditions generally occur when a genetically predisposed person is exposed to a trigger, usually something environmental, according to Elliot Rosenstein, M.D., one of the directors of the Institute for Rheumatic & Autoimmune Disease at Overlook Medical Center in Summit, New Jersey.

"For some diseases, the genetics and the environmental exposures are well understood; for others, we have yet to elucidate these factors fully," Rosenstein wrote in an email interview.

For example, he noted that specific variants of the HLA-DQ2 and HLA-DQ8 genes are associated with celiac disease, but the condition only develops when a person with one of these genetic variants consumes gluten.

Similarly, certain types of streptococcus infections can trigger rheumatic fever, and exposure to the Epstein-Barr virus is linked to several autoimmune diseases.

'Having an autoimmune disorder makes you more susceptible to additional autoimmune conditions, and many people have more than one.'

Pregnancy and giving birth are also associated with the onset of certain autoimmune diseases, such as Hashimoto's thyroiditis.

Other risk factors associated with autoimmune conditions include smoking, periodontal disease, exposure to toxins, an inflammatory diet and certain medications. Existing autoimmune conditions increase the risk of subsequent disorders.

Being female also increases a person's risk of autoimmunity in general. This population is three times more susceptible than males, according to Hana Patel, M.B.B.S., a general practitioner and mental health coach in London.

The reason isn't certain, but genetics and hormones may play a part, according to Mahmud Kara, M.D., founder and CEO of KaraMD, a supplements manufacturer in Cleveland.

Researchers have found the X chromosome—of which females have two—more heavily expresses certain genes related to immunity. And estrogen, of which females have significantly more than men, affects the immune system considerably.

Type and stages

Each autoimmune condition affects different body parts in distinct ways. Multiple sclerosis, for instance, impacts the nervous system. Hashimoto's acts upon the endocrine system, and rheumatoid arthritis can affect one or more organs.

Having an autoimmune disorder makes you more susceptible to additional autoimmune conditions, and many people have more than one.

According to the National Institutes of Health (NIH) and National Stem Cell Foundation (NSCF), some of the most common immune disorders include the following:

• Addison's disease
• Graves' disease
• Hashimoto's thyroiditis
• Celiac disease
• Dermatomyositis
• Multiple sclerosis (MS)
• Pernicious anemia
• Psoriasis
• Inflammatory bowel disease (IBD)
• Reactive arthritis
• Rheumatoid arthritis
• Crohn's disease
• Scleroderma
• Myasthenia gravis
• Type 1 diabetes
• Systemic lupus
• Sjögren's syndrome

All of these diseases behave differently, according to Rosenstein and Patel. However, if not addressed, most autoimmune conditions can cause substantial, widespread and permanent damage.

In most cases, disease progression happens gradually over several years. Medical management and lifestyle changes can often slow or stop this process and help to mitigate symptoms.

Socioeconomic and cultural factors

Research indicates people with fewer resources are more vulnerable to health problems, including autoimmunity. This may be partly because people in lower socioeconomic groups are more likely to be exposed to certain chemicals and viruses that can trigger autoimmune diseases.

Pollution exposure, for example, is associated with the development of rheumatoid arthritis, according to Rosenstein. Healthcare inequities and lack of access to care may also increase people's risk.

People of multiple demographics can absolutely face such barriers, but marginalized people are disproportionately affected. Different ethnic groups are more susceptible to certain types of autoimmunity, Rosenstein noted. For example, Black women are three times more likely to get lupus than their white counterparts. The condition is also more common in Hispanic, Asian, Native American and Alaskan Native people.

Rheumatoid arthritis, type 1 diabetes, multiple sclerosis and autoimmune hepatitis are likewise more prevalent in marginalized groups.

How debilitating can autoimmunity be?

Depending on the condition and its severity, autoimmunity can be debilitating, preventing a person from going to work or performing activities of daily living, such as chores, errands and personal care.

At the very least, the symptoms associated with many autoimmune conditions—chronic pain, fatigue, gastrointestinal distress, depression, anxiety—can considerably affect a person's well-being and quality of life.

In some cases, autoimmune conditions can be life-threatening, according to Patel. These conditions include anti-NMDA receptor encephalitis, mixed connective tissue disease, autoimmune vasculitis and giant cell myocarditis.

Others, such as rheumatoid arthritis, can produce complications that shorten a person's life span.

Facts and stats

Research during the past few decades suggests autoimmune diseases are becoming more common worldwide. Nearly 4 percent of the world's population and 5 percent to 8 percent of the U.S. population has at least one autoimmune disease.

While some specific conditions are rare, autoimmunity in general is one of the most prevalent causes of chronic illness globally. These diseases are among the top 10 causes of death in women of all age groups up to age 64.

Advances in diagnostics have contributed to a better understanding of the disorders. Not long ago, scientists discovered that certain conditions—hypothyroidism and type 1 diabetes mellitus are two—can have an autoimmune etiology, or cause.

However, recent studies show antinuclear antibodies (ANA)—the most common indicator of autoimmune disorders—have become increasingly prevalent in the United States, and most experts believe multiple factors are at play.

"One cause that researchers point to is environmental lifestyle changes, specifically when it comes to the increased presence of toxins, nutrient-deficient refined foods and additives that contribute to chronic inflammation," Kara concluded.

Of course, talking with a physician should be your first step if you've noticed new, unexplained symptoms, whether they're due to an autoimmune disorder or something else. Don't have a doctor you see regularly? You should. Fortunately, telehealth makes it easy to connect with a doctor who can answer your questions and evaluate your situation. Many physicians offer video visits and same-day appointments. Giddy Telehealth is an easy-to-use online portal that provides access to hundreds of healthcare professionals whose expertise covers the full scope of medical care.