Autoimmune Diseases: Why Your Immune System Turns on Your Body and How It's Managed

Medically reviewed by Dr. Baraa Alnahhal, MD. Last reviewed October 17, 2026. This content is for educational purposes and is not medical advice.

Figure 1. Your immune system normally defends the body against viruses, bacteria, and toxins. In an autoimmune disease, it mistakes your own cells for threats and damages healthy tissue.

Quick Answer

Autoimmune diseases are a group of more than 100 conditions in which the immune system mistakes healthy tissue for an invader and damages it [1]. Around 1 in 15 people in the U.S. has one [1]. Symptoms vary widely and often flare up, then quiet down [1]. There is no cure, but medicines and therapies help control symptoms, and some diseases enter remission [1].

What the research says

• Autoimmune diseases affect roughly 1 in 10 people in a very large UK study, and they are becoming more common. Among 22,009,375 people followed from 2000 to 2019, 978,872 received a new diagnosis of at least one of 19 common autoimmune diseases. Together these diseases affected 10.2% of the population (13.1% of women and 7.4% of men). Overall incidence rose over the study period (incidence rate ratio 1.04; 95% CI 1.00 to 1.09), with the largest increases in celiac disease (2.19), Sjögren’s syndrome (2.09), and Graves’ disease (2.07). Prevalence estimates differ by country and by which conditions are counted (Conrad et al., The Lancet, 2023) [6].

• Having one autoimmune disease raises the odds of another. In the same study, people with childhood-onset type 1 diabetes had much higher rates of Addison’s disease (incidence rate ratio 26.5; 95% CI 17.3 to 40.7), celiac disease (28.4; 25.2 to 32.0), Hashimoto’s thyroiditis (13.3; 11.8 to 14.9), and Graves’ disease (6.7; 5.1 to 8.5). Multiple sclerosis, by contrast, had a particularly low rate of co-occurrence with other autoimmune diseases (Conrad et al., The Lancet, 2023) [6].

• Viral infections are one of the environmental triggers. A review explained that autoimmune diseases follow a breach in immune tolerance, and that viral infections can lead to autoimmunity through mechanisms such as molecular mimicry, epitope spreading, and bystander activation. It also covered recent findings on COVID-19 and the development of autoimmune diseases, and noted that the worldwide incidence and prevalence of autoimmune diseases are increasing (Sundaresan et al., Viruses, 2023) [5].

What Are Autoimmune Diseases?

Autoimmune diseases are health conditions that happen when your immune system attacks your body instead of defending it [1]. Healthcare providers sometimes call them autoimmune disorders.

Imagine your body is a castle and your immune system is an army fighting off invaders like germs. If the army malfunctions and attacks the castle itself, you may have an autoimmune disease.

Usually, your immune system is like your body’s built-in security system. It automatically detects substances that shouldn’t be in your body, like viruses, bacteria, or toxins, and sends out white blood cells to eliminate them before they can damage your body or make you sick [1].

If you have an autoimmune disease, your immune system is more active than it should be [1]. Because there aren’t invaders to attack, your immune system turns on your body and damages healthy tissue.

Autoimmune diseases are chronic conditions [1] [3]. This means if you have one, you’ll probably have to manage it and the symptoms it causes for the rest of your life.

How Many Autoimmune Diseases Are There?

There are more than 100 different autoimmune diseases [1] that can affect almost any part of your body. They can affect almost any tissue or organ, depending on where your immune system malfunctions, including your joints, muscles, skin, blood vessels, digestive system, endocrine system, and nervous system [1].

How Common Are Autoimmune Diseases?

Autoimmune diseases are common, especially because there are so many different types. Experts estimate that around 1 in 15 people in the U.S. has an autoimmune disease [1].

What Are the Types of Autoimmune Diseases?

This isn’t a complete list, but here are examples of autoimmune conditions and the body systems they affect:

Body System	Example Conditions
Joints and muscles	Rheumatoid arthritis (RA), lupus, myositis
Skin and blood vessels	Sjögren’s syndrome, psoriasis, psoriatic arthritis, dermatomyositis, scleroderma, vasculitis, rheumatoid vasculitis, urticarial vasculitis, vitiligo
Digestive system	Crohn’s disease, celiac disease, ulcerative colitis, autoimmune gastritis
Endocrine system	Type 1 diabetes, Addison’s disease, Hashimoto’s thyroiditis, Graves’ disease
Nervous system	Multiple sclerosis (MS), myasthenia gravis (MG), Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy (CIDP)

What Are the Symptoms of Autoimmune Diseases?

Autoimmune diseases can cause a wide range of symptoms. They can affect your body almost literally from head to toe [1].

For example, conditions that affect your muscles can cause muscle weakness [1]. You might also have joint pain, swelling, or feel stiffness if you have a condition like rheumatoid arthritis [1]. Type 1 diabetes causes high blood sugar (hyperglycemia) [1]. Some autoimmune conditions affect your vision [1].

Many autoimmune diseases cause inflammation, which can include a feeling of warmth or heat, discoloration or redness on your skin, swelling, and pain [1] [3].

Symptom Type	What You Might Notice
Joint and muscle symptoms	Joint pain, swelling, stiffness, muscle weakness
Inflammation signs	Warmth or heat, skin discoloration or redness, swelling, pain
System-specific signs	High blood sugar (Type 1 diabetes), vision changes
Symptom pattern	Flares or attacks: episodes where symptoms are more noticeable or severe, then come and go

Lots of autoimmune diseases cause symptoms that come and go (recur). These episodes of more noticeable or more severe symptoms are called flares or attacks [1]. Tell your provider if you experience symptoms that seem to recur, especially if certain physical activities, times of day, foods or drinks, or anything else makes them noticeably better or worse.

Nobody knows what’s normal for your body better than you. Visit a healthcare provider if you notice any new symptoms you can’t explain, especially if you don’t feel like yourself more often than usual.

Figure 2. Autoimmune disease symptoms can show up almost anywhere, including joints, muscles, skin, blood sugar, and vision, and many come with inflammation signs like warmth, redness, and swelling.

What Causes Autoimmune Diseases?

Experts don’t know for certain what causes autoimmune diseases [1] [3]. We know your immune system mistakenly damaging your body instead of protecting it causes the symptoms you experience. But researchers are still studying what makes your immune system start hurting you in the first place.

What Are the Risk Factors?

Some studies have found that certain factors (triggers) might increase your risk of developing an autoimmune disease [1]:

Risk Factor	What the Research Says
Viral infections	Including COVID-19 and Epstein-Barr virus
Sex	Women are more likely to have autoimmune conditions
Family history	Some autoimmune conditions are genetic and pass through generations of a biological family
Having one autoimmune disease	Increases the odds of developing another one (multiple autoimmune syndrome)
Environmental exposure	Chemicals or other aspects of where you live or work that impact your health might trigger autoimmune diseases
Tobacco use	Smoking and other types of tobacco can cause many health issues, including potentially triggering autoimmune diseases

How Are Autoimmune Diseases Diagnosed?

Healthcare providers diagnose autoimmune diseases with a physical exam and by discussing your health history [1]. You might also need some tests.

Your provider will examine your body, especially if you’re experiencing symptoms in a specific area. They’ll ask about the symptoms you’re experiencing and when you first noticed them. Tell your provider if you know any of your biological family members have an autoimmune disease.

Diagnosing an autoimmune disease is often a differential diagnosis. This means your provider will test you for several different conditions that can cause the symptoms you’re experiencing until they find the cause [1].

Your provider might order blood tests to look for specific signs (markers) of autoimmune diseases [1] [3]. These markers are like clues your immune system leaves behind after it damages your body or causes specific issues.

You might need some imaging tests to take pictures of the insides of your body, including X-rays, MRI (magnetic resonance imaging), CT scan (computed tomography scan), and ultrasound [1].

Diagnostic Step	What Happens
Physical exam	Provider examines your body, especially areas where you have symptoms
Health history	Questions about symptoms, when they started, and family history of autoimmune disease
Differential diagnosis	Testing for several possible conditions until the true cause is found
Blood tests	Looking for markers, the clues your immune system leaves behind after damaging tissue
Imaging tests	X-rays, MRI, CT scan, ultrasound to picture the inside of your body

How Are Autoimmune Diseases Treated?

Autoimmune diseases can need a variety of treatments. Just like the wide variety of symptoms they cause, which treatments you’ll need depends on which condition you have. Everyone’s immune system, genetics, and environment are different. That means the treatments that work for you will be unique.

Some common treatments to manage autoimmune disease symptoms include pain relievers; anti-inflammatory medication like NSAIDs (nonsteroidal anti-inflammatory drugs) or corticosteroids; immunosuppressants; physical therapy; occupational therapy; and IVIG (intravenous immunoglobulin) infusions [1] [3].

You might need specific treatments based on the condition you have. For example, people with Type 1 diabetes need insulin therapy [1], and people with celiac disease need to eat a gluten-free diet [1].

Treatment Category	Examples
Pain relief	Pain relievers
Reduce inflammation	NSAIDs, corticosteroids
Calm the immune response	Immunosuppressants, IVIG infusions
Movement and function	Physical therapy, occupational therapy
Condition-specific	Insulin therapy for Type 1 diabetes; gluten-free diet for celiac disease

Figure 3. Diagnosis works by ruling conditions out one at a time, and treatment is matched to the individual condition. There’s no cure, but symptoms can be managed and some diseases enter remission, long quiet stretches between flares.

Can Autoimmune Diseases Be Cured?

There’s no cure for autoimmune diseases [1]. They’re chronic (long-term) conditions that usually last your whole life [1] [3]. Some autoimmune diseases enter remission, a long period of time between symptom flares [1]. This isn’t the same as a cure, but it might mean the symptoms impact your daily routine less often.

Can You Prevent Autoimmune Diseases?

There might not be any way to prevent autoimmune diseases because experts aren’t sure what causes them [1].

Is an Autoimmune Disease Serious?

Living with an autoimmune disease like lupus, rheumatoid arthritis, and multiple sclerosis can be complex and serious [1]. Although there are no cures for these diseases, many of their symptoms can be treated, and sometimes they go into remission [1]. Stay in touch with your healthcare provider about any advances in understanding and treating autoimmune diseases.

What Is the Life Expectancy of Someone With an Autoimmune Disease?

It’s hard to give an estimate of how an autoimmune disease will affect your lifespan (how long you live). Some conditions are more serious than others, and can cause fatal complications [1].

Conditions like multiple sclerosis and myositis are more likely to be fatal than many autoimmune diseases, but that doesn’t mean they always are [1]. Similarly, Type 1 diabetes can be fatal if it’s not managed [1].

Talk to your healthcare provider. They’ll explain how an autoimmune disease will affect your lifespan (if at all).

How Do I Take Care of Myself?

Everyone’s body and journey with an autoimmune disease is different. Talk to your healthcare provider about the best ways to manage the symptoms you experience. You might need to adjust the kinds of physical activities you do, the foods and drinks you consume, or make other tweaks to your day-to-day routine.

When Should I See My Healthcare Provider?

Visit a healthcare provider if you’re experiencing new or worsening symptoms you can’t explain, especially if they affect your ability to do all your usual activities.

If you’ve already been diagnosed with an autoimmune disease, tell your provider if it feels like your treatments aren’t working as well as they used to or if the symptoms are recurring more often.

When Should I Go to the Emergency Room?

Go to the ER or call 911 (or your local emergency services number) if you experience any of the following severe symptoms [1]:

• Trouble breathing or shortness of breath (dyspnea)

• Severe chest pain or pressure

• Sudden, unusually serious or intense headache

• Sudden weakness, especially if you can’t move

• Dizziness that doesn’t stop

• Pain so severe you can’t stand it

What Questions Should I Ask My Provider?

You may want to ask your provider which tests you will need, whether your condition is genetic, what kinds of treatments will manage your symptoms, and how you will need to change your daily routine.

Conclusion: When the Body’s Army Attacks the Castle

An autoimmune disease is one of the most confusing things a person can be diagnosed with: the system built to protect you becomes the thing that hurts you. There are more than 100 different autoimmune diseases, and they can strike almost any organ (joints, skin, gut, hormones, nerves), affecting roughly 1 in 15 people in the U.S. [1] While experts still don’t know exactly what triggers them, studies point to viral infections like COVID-19 and Epstein-Barr virus, being a woman, family history, environmental exposures, and tobacco use as potential risk factors [1].

There’s no cure, and that reality can feel overwhelming. But treatments exist for nearly every type: pain relievers, anti-inflammatories, immunosuppressants, therapy, and condition-specific care like insulin for Type 1 diabetes [1], and many people experience remission, long stretches where symptoms barely interfere with daily life. Because symptoms often flare and fade, keeping a close eye on your body, and telling your provider when patterns change, is one of the most powerful things you can do. Trust your instincts about what’s normal for you, celebrate the small victories, and remember you’re not defined by the condition. Explore Rinnit.com’s library of autoimmune and chronic condition guides for more plain-language answers.

Frequently Asked Questions

What is an autoimmune disease? An autoimmune disease is a health condition that happens when your immune system attacks your body instead of defending it. Healthcare providers sometimes call them autoimmune disorders.

How does an autoimmune disease work? Your immune system is normally like a built-in security system. It detects invaders like viruses, bacteria, or toxins and sends out white blood cells to eliminate them. In an autoimmune disease, the immune system is overactive. With no invaders to attack, it turns on your body and damages healthy tissue.

How many autoimmune diseases are there? There are more than 100 different autoimmune diseases that can affect almost any part of your body.

How common are autoimmune diseases? Autoimmune diseases are common. Experts estimate that around 1 in 15 people in the U.S. has an autoimmune disease.

What are the symptoms of autoimmune diseases? Symptoms vary widely depending on the condition and can affect your body almost literally from head to toe: muscle weakness, joint pain, swelling, and stiffness; skin redness, discoloration, warmth, and swelling from inflammation; high blood sugar with Type 1 diabetes; and vision changes in some conditions. Symptoms often come and go in episodes called flares or attacks.

What causes autoimmune diseases? Experts don’t know for certain. We know the immune system mistakenly damages your body instead of protecting it, but researchers are still studying what makes your immune system start hurting you in the first place.

What increases my risk of an autoimmune disease? Studies suggest triggers may include viral infections (including COVID-19 and Epstein-Barr virus), being a woman, having biological relatives with autoimmune diseases (some are genetic), having one autoimmune disease already (multiple autoimmune syndrome), exposure to chemicals or environmental factors, and smoking or other tobacco use.

How are autoimmune diseases diagnosed? Through a physical exam, health history, and often a differential diagnosis, which means testing for several possible conditions until the true cause is found. Blood tests look for markers, clues your immune system leaves behind after damaging tissue, and imaging like X-rays, MRI, CT scans, or ultrasound may be used.

What treatments are available? Common treatments include pain relievers, anti-inflammatory medications (NSAIDs, corticosteroids), immunosuppressants, physical therapy, occupational therapy, and IVIG infusions. Some conditions need specific treatment, such as insulin therapy for Type 1 diabetes or a gluten-free diet for celiac disease.

Can autoimmune diseases be cured? There’s no cure for autoimmune diseases. They’re chronic conditions that usually last your whole life. Some enter remission, long periods between symptom flares, which means symptoms may impact your daily routine less often, but remission isn’t a cure.

Can autoimmune diseases be prevented? There might not be any way to prevent them because experts aren’t sure what causes them.

Is an autoimmune disease serious? Living with conditions like lupus, rheumatoid arthritis, or multiple sclerosis can be complex and serious. Although there are no cures, many symptoms can be treated, and some diseases go into remission. Stay in touch with your provider about advances in treatment.

How does an autoimmune disease affect life expectancy? It’s hard to estimate. Some conditions are more serious and can cause fatal complications. Multiple sclerosis and myositis are more likely to be fatal than many autoimmune diseases, though that doesn’t mean they always are, and Type 1 diabetes can be fatal if not managed. Your provider can explain how your specific condition may affect your lifespan.

When should I see a healthcare provider? Visit a provider for new or worsening symptoms you can’t explain, especially if they affect your ability to do your usual activities. If you’re already diagnosed, tell your provider if treatments aren’t working as well as they used to or symptoms are recurring more often.

When should I go to the emergency room? Go to the ER or call 911 (or your local emergency number) for trouble breathing or shortness of breath, severe chest pain or pressure, a sudden unusually intense headache, sudden weakness especially if you can’t move, dizziness that doesn’t stop, or pain so severe you can’t stand it.

Related Reading

Learn more in our guide to Antibody Test (Serology): What It Detects, Uses and What Results Mean.

ANA Test (Antinuclear Antibody Test): Purpose, Results and What a Positive Means explains how this blood test looks for autoimmune disease and what a positive result means.

References

1. Cleveland Clinic. Autoimmune Diseases. Cleveland Clinic. Updated October 22, 2024. https://my.clevelandclinic.org/health/diseases/21624-autoimmune-diseases

2. Global Autoimmune Institute. Autoimmune Disease Basics. Global Autoimmune Institute. Accessed October 14, 2026. https://www.autoimmuneinstitute.org/understanding-autoimmune-disease/

3. Fernandez J. Autoimmune Disorders. Merck Manual Consumer Version. Updated September 2026. https://www.merckmanuals.com/home/immune-disorders/allergic-reactions-and-other-hypersensitivity-disorders/autoimmune-disorders

4. National Institute of Arthritis and Musculoskeletal and Skin Diseases. Overview of Autoimmune Diseases. National Institute of Arthritis and Musculoskeletal and Skin Diseases. Accessed October 14, 2026. https://www.niams.nih.gov/health-topics/autoimmune-diseases

5. Sundaresan B, et al. The Role of Viral Infections in the Onset of Autoimmune Diseases. Viruses. 2023;15(3):782. PMID 36992490. https://doi.org/10.3390/v15030782

6. Conrad N, et al. Incidence, prevalence, and co-occurrence of autoimmune disorders over time and by age, sex, and socioeconomic status: a population-based cohort study of 22 million individuals in the UK. Lancet. 2023;401(10391):1878-1890. PMID 37156255. https://doi.org/10.1016/S0140-6736(23)00457-9

Medical Disclaimer

This article is for general informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read here.