A healthy immune system defends the body against disease and infection. But if the immune system malfunctions, it mistakenly attacks healthy cells, tissues, and organs. Called autoimmune disease, these attacks can affect any part of the body, weakening bodily function and even turning life-threatening.

Scientists know about more than 80 autoimmune diseases. Some are well known, such as type 1 diabetes, multiple sclerosis, lupus, and rheumatoid arthritis, while others are rare and difficult to diagnose. With unusual autoimmune diseases, patients may suffer years before getting a proper diagnosis. Most of these diseases have no cure. Some require lifelong treatment to ease symptoms.

Collectively, these diseases affect more than 24 million people in the United States. An additional eight million people have auto-antibodies, blood molecules that indicate a person’s chance of developing autoimmune disease. Autoimmune diseases are affecting more people for reasons unknown. Likewise, the causes of these diseases remain a mystery.

Studies indicate these diseases likely result from interactions between genetic and environmental factors. Gender, race, and ethnicity characteristics are linked to a likelihood of developing an autoimmune disease. Autoimmune diseases are more common when people are in contact with certain environmental exposures.

Your body’s disease defense system, called the immune system, goes to battle every day. It helps keep you healthy by fighting off viruses and bacteria that sneak into your body. But sometimes, your immune system makes mistakes. If it sees your body’s healthy cells as a threat, it may attack them. This can cause an autoimmune disorder.

There are many different autoimmune diseases. Some involve only one type of tissue. For example, in a disease called vasculitis, your immune system attacks your blood vessels. Other autoimmune diseases involve many different parts of the body. Lupus, for example, can damage the skin, heart, lungs, and more.

Most autoimmune diseases cause inflammation. But the symptoms they cause depend on the body parts affected. You can have pain in your joints or muscles. Or you may experience skin rashes, fevers, or fatigue.

Researchers still don’t know what causes most autoimmune diseases. But they’ve made progress in understanding what puts you at risk and figuring out ways to diagnose and treat them.

What Are the Triggers?

Some autoimmune diseases are rare, but others are fairly common. About 1% of people in the U.S. have rheumatoid arthritis, explains Dr. Mariana Kaplan, an NIH specialist in autoimmune diseases. Rheumatoid arthritis damages the joints.

Certain genes put you at higher risk for developing an autoimmune disorder. But genes alone aren’t usually enough, says Dr. Peter Grayson, an NIH expert on vasculitis. His team recently found a single gene change that can cause vasculitis in older men.

Most people who carry genes linked with autoimmune diseases still won’t develop one. Usually, one or more triggers are needed to set off the immune system.

Different things in your environment can serve as triggers, explains Dr. Andrew Mammen, an NIH expert on muscle diseases. His team studies myositis, a disease in which immune cells attack the muscles.

Too much sun exposure can trigger a type of myositis in people who have certain genetic risk factors, Mammen explains. But, he says, most people need other triggers as well to develop the condition. What they are aren’t always clear.

Certain viruses can also jump-start an autoimmune attack. A recent NIH-funded study found that a virus called Epstein-Barr may trigger some cases of multiple sclerosis, or MS. MS is an autoimmune disease that damages the nerves.

Other risk factors can be your age, sex, smoking history, and weight. Many autoimmune diseases are also more common in women than men.

Getting a Diagnosis

A diagnosis of an autoimmune disease can take time, says Grayson. Especially if it’s one that affects many parts of the body.

People often turn to different doctors for different symptoms. “If you’re seeing, for example, an eye doctor, a skin doctor, and a lung doctor separately, they may not see that your symptoms are connected,” says Grayson.

Symptoms of autoimmune diseases can also mimic those of many other conditions. “For example, we call lupus ‘the great imitator,’ because it can look like many other diseases,” Kaplan says.

Talk with your health care provider if you’re having muscle, bone, or joint pain that’s not related to an injury. Or if you’ve had pain in multiple areas or for long periods of time. They may refer you to a rheumatologist. This is a doctor who specializes in diseases that cause inflammation.

Your doctor may use blood tests to look for antibodies that are attacking your own tissues. These are called autoantibodies. But having them in your blood isn’t enough to be diagnosed with an autoimmune disease. Many people have them in their blood but don’t get sick, Kaplan explains.

Imaging technologies can be used to look for signs of an autoimmune disorder, too. X-rays can show joint issues. MRIs can reveal damage deep in the body.

Researchers are trying to find new ways to use imaging to help diagnose or monitor autoimmune disease. Grayson’s lab is testing whether PET scans can find hidden inflammation in the blood vessels of people with vasculitis.

Tamping Down the Attack

There are no cures for autoimmune disorders yet. But researchers have made progress in managing symptoms.

Drugs called corticosteroids are often the first treatment for an autoimmune disease. “They work quickly, and they’re effective,” Mammen says.

But steroids suppress your entire immune system. So they can have serious side effects. These include high blood pressure, bone loss, and weight gain.

Other drugs suppress only parts of the immune system. These tend to have fewer side effects and can be used for longer. Some of these drugs get rid of cells that make certain antibodies. Others target specific immune-system proteins. One such drug was recently the first new drug approved for lupus in a decade.

You may need to try several different drugs to find the one that works best to control your symptoms, Grayson says. It’s important to work with your doctor to balance quality of life with treating the disease, he adds.

Lifestyle changes can also help control symptoms. Movement is especially important for autoimmune diseases that affect the muscles, like myositis and MS, Mammen says. “We actually prescribe exercise,” he says. “It’s not optional; it’s part of the treatment.”

Talk with your health care provider about different activities you can try. Low-impact workouts like yoga, water aerobics, or walking can be helpful for some people.

Quitting smoking can help those whose disease affects their blood vessels, Grayson says.

Researchers are working to develop better treatments. NIH projects are bringing together scientists, nonprofit groups, and drug companies to find new treatments and research tools for autoimmune diseases.

Researchers also want to find ways to detect autoimmune diseases before they cause symptoms, Mammen explains. “Maybe there’s a time period where early treatment could put the brakes on one developing,” he says.

Autoimmune Disease Symptoms

Symptoms of autoimmune diseases can mimic those of other problems. Common ones include:

• Redness, heat, pain, and swelling in one or more parts of the body
• Feeling tired all the time (fatigue)
• Joint pain and stiffness
• Muscle aches or weakness
• Skin problems such as rashes, sores, and dry or scaly skin
• Shortness of breath or trouble breathing
• Fever that comes and goes
• Loss of appetite

The immune system is a network of cells and organs that work together to fight infections and protect the body against diseases. For example, the skin and mucus membranes help prevent harmful germs from entering the body, and the organs and tissues of the lymphatic system (including the spleen, tonsils, thymus gland, bone marrow, and lymph nodes) create and store the white blood cells that fight infection.

In a healthy immune response, the immune system creates lymphocytes (a type of white blood cell) and antibodies (protective proteins) that identify unfamiliar substances called antigens and attack them to protect the body. 

Typically, the immune system can tell the difference between the body’s own cells and tissues and potentially harmful intruders such as viral and bacterial antigens. In people with autoimmune conditions, the immune system gets confused and produces autoantibodies, a type of antibody that attacks healthy cells and tissues. This can lead to inflammation in different parts of the body, harm the body’s organs and systems, and contribute to a wide range of symptoms.

Thought to be one of the most complicated systems in the human body, our immune system has effects on most aspects of health and disease. It protects us from harm, such as infectious organisms, and it helps us heal through wound healing and other processes. Most of the time, our immune system does a remarkable job distinguishing outside invaders from our own cells, but sometimes it mistakenly attacks the body's own organs, tissues, and cells. Autoimmune disorders are the result, and they appear to be on the rise.

Autoimmune disorders are a major issue for women's health, since the prevalence of these conditions is much higher in women, and some are more prevalent in women that are Black, Hispanic, American Indian, Hawaiian/Pacific Islander, or Asian. More than 80 types of autoimmune conditions exist, but some examples include inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, Sjögren's syndrome, and lupus.

Estimates say that about 80 percent of those affected by autoimmune disorders are women, but a few autoimmune disorders, such as type-1 diabetes and ankylosing spondylitis, are more common in men than in women. Disease severity also differs by sex: for example, although more women get lupus and multiple sclerosis than do men, these conditions affect males more severely.

• Researchers often study multiple sclerosis (MS) in mice: they get a similar condition called experimental autoimmune encephalomyelitis (EAE). Some of these studies are showing promise in humans, such as one small clinical trial that found a protective role for testosterone in males with MS.
• Certain brain regions were thinner than other brain regions in women with the painful condition irritable bowel syndrome. The changes corresponded with pain severity and did not occur in men with the disorder, suggesting that different brain mechanisms might be causing this type of pain in females and males.
• Novel transgenic mouse models can distinguish between the effects of sex hormones (such as estrogen and testosterone) and sex chromosomes (XX and XY) on disease. Scientists have learned that, in mice, the female chromosome set (XX) stimulates the development of lupus.
• Gene expression in the salivary glands, which are impaired in Sjögren's syndrome, differs markedly between women and men.
• Lupus flare-ups can signal pre-term birth in pregnant women with a mild version of the condition. A 2013 study showed that certain molecular markers identified midway through pregnancy may prove to be clinically useful in identifying women at risk for complications.

What are autoimmune diseases?

Your immune system protects you from disease and infection by attacking germs that get into your body, such as viruses and bacteria. Your immune system can tell that the germs aren't part of you, so it destroys them. If you have an autoimmune disease, your immune system attacks the healthy cells of your organs and tissues by mistake.

There are more than 80 types of autoimmune diseases. They can affect almost any part of your body. For example, alopecia areata is an autoimmune disease of the skin that causes hair loss. Autoimmune hepatitis affects the liver. In type 1 diabetes, the immune system attacks the pancreas. And in rheumatoid arthritis, the immune system can attack many parts of the body, including the joints, lungs, and eyes.

What causes autoimmune diseases?

No one is sure why autoimmune diseases happen. But you can't catch them from other people.

Autoimmune diseases do tend to run in families, which means that certain genes may make some people more likely to develop a problem. Viruses, certain chemicals, and other things in the environment may trigger an autoimmune disease if you already have the genes for it.

Who is at risk for autoimmune diseases?

Millions of Americans of all ages have autoimmune diseases. Women develop many types of autoimmune diseases much more often than men. And if you have one autoimmune disease, you are more likely to get another.

What are the symptoms of autoimmune diseases?

The symptoms of an autoimmune disease depend on the part of your body that's affected. Many types of autoimmune diseases cause redness, swelling, heat, and pain, which are the signs and symptoms of inflammation. But other illnesses can cause the same symptoms.

The symptoms of autoimmune diseases can come and go. During a flare-up, your symptoms may get severe for a while. Later on, you may have a remission, which means that your symptoms get better or disappear for a period of time.

How are autoimmune diseases diagnosed?

Doctors often have a hard time diagnosing autoimmune diseases. There's usually not a specific test to show whether you have a certain autoimmune disease. And the symptoms can be confusing. That's because many autoimmune diseases have similar symptoms. And some symptoms, such as muscle aches, are common in many other illnesses. So it can take a long time and some visits to different types of doctors to get a diagnosis.

To help your doctor find out if an autoimmune disease is causing your symptoms,:

• Learn about the health conditions in your family history. What health problems did your grandparents, aunts, uncles, and cousins have? Write down what you learn and share it with your doctor.
• Keep track of your symptoms, including how long they last and what makes them better or worse. Share your notes with your doctor.
• See a specialist who deals with the symptoms that bother you most. For example, if you have rash, see a dermatologist (skin doctor).

What are the treatments for autoimmune diseases?

The treatment depends on the disease. In most cases, the goal of treatment is to suppress (slow down) your immune system, and ease swelling, redness, and pain from inflammation. Your doctor may give you corticosteroids or other medicines to help you feel better. For some diseases, you may need treatment for the rest of your life.

There are more than 80 known autoimmune conditions, which together affect more than 23.5 million Americans. Each disease is different, but what they all have in common is a haywire immune response that turns the immune system against the body it is supposed to protect. 

Some conditions target specific organs or tissues, such as the skin, heart, or blood vessels. Others are more general, targeting multiple tissue or organ systems throughout the body. 

Examples of common organ-specific conditions include type 1 diabetes (pancreas), inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis (digestive tract), and multiple sclerosis (brain and spinal cord). Systemic conditions—those that attack multiple systems—include systemic lupus erythematosus, also known as lupus or SLE, Sjögren’s syndrome, and scleroderma, which all affect tissues and organs throughout the body.

Some autoimmune diseases are considered organ specific, meaning that the immune system targets specific organs or tissues. Examples of organ-specific autoimmune diseases include celiac disease, Graves disease, Hashimoto thyroiditis, type I diabetes mellitus, and Addison disease.

Celiac Disease

Celiac disease is largely a disease of the small intestine, although other organs may be affected. People in their 30s and 40s, and children are most commonly affected, but celiac disease can begin at any age. It results from a reaction to proteins, commonly called gluten, found mainly in wheat, barley, rye, and some other grains. The disease has several genetic causes (predispositions) and poorly understood environmental influences. On exposure to gluten, the body produces various autoantibodies and an inflammatory response. The inflammatory response in the small intestine leads to a reduction in the depth of the microvilli of the mucosa, which hinders absorption and can lead to weight loss and anemia. The disease is also characterized by diarrhea and abdominal pain, symptoms that are often misdiagnosed as irritable bowel syndrome.

Diagnosis of celiac disease is accomplished from serological tests for the presence of primarily IgA antibodies to components of gluten, the transglutinaminase enzyme, and autoantibodies to endomysium, a connective tissue surrounding muscle fibers. Serological tests are typically followed up with endoscopy and biopsy of the duodenal mucosa. Serological screening surveys have found about 1% of individuals in the United Kingdom are positive even though they do not all display symptoms. This early recognition allows for more careful monitoring and prevention of severe disease.

Celiac disease is treated with complete removal of gluten-containing foods from the diet, which results in improved symptoms and reduced risk of complications. Other theoretical approaches include breeding grains that do not contain the immunologically reactive components or developing dietary supplements that contain enzymes that break down the protein components that cause the immune response.

Disorders of the Thyroid

Graves disease is the most common cause of hyperthyroidism in the United States. Symptoms of Graves disease result from the production of thyroid-stimulating immunoglobulin (TSI) also called TSH-receptor antibody. TSI targets and binds to the receptor for thyroid stimulating hormone (TSH), which is naturally produced by the pituitary gland. TSI may cause conflicting symptoms because it may stimulate the thyroid to make too much thyroid hormone or block thyroid hormone production entirely, making diagnosis more difficult. Signs and symptoms of Graves disease include heat intolerance, rapid and irregular heartbeat, weight loss, goiter (a swollen thyroid gland, protruding under the skin of the throat) and exophthalmia (bulging eyes) often referred to as Graves ophthalmopathy.

The most common cause of hypothyroidism in the United States is Hashimoto thyroiditis, also called chronic lymphocytic thyroiditis. Patients with Hashimoto thyroiditis often develop a spectrum of different diseases because they are more likely to develop additional autoimmune diseases such as Addison disease (discussed later in this section), type 1 diabetes, rheumatoid arthritis, and celiac disease. Hashimoto thyroiditis is a T_H1 cell-mediated disease that occurs when the thyroid gland is attacked by cytotoxic lymphocytes, macrophages, and autoantibodies. This autoimmune response leads to numerous symptoms that include goiter, cold intolerance, muscle weakness, painful and stiff joints, depression, and memory loss.

Type 1 Diabetes

Juvenile diabetes, or type 1 diabetes mellitus, is usually diagnosed in children and young adults. It is a T-cell-dependent autoimmune disease characterized by the selective destruction of the β cells of the islets of Langerhans in the pancreas by CD4 T_H1-mediated CD8 T cells, anti-β-cell antibodies, and macrophage activity. There is also evidence that viral infections can have either a potentiating or inhibitory role in the development of type 1 diabetes (T1D) mellitus. The destruction of the β cells causes a lack of insulin production by the pancreas. In T1D, β-cell destruction may take place over several years, but symptoms of hyperglycemia, extreme increase in thirst and urination, weight loss, and extreme fatigue usually have a sudden onset, and diagnosis usually does not occur until most β cells have already been destroyed.

Autoimmune Addison Disease

Destruction of the adrenal glands (the glands lying above the kidneys that produce glucocorticoids, mineralocorticoids, and sex steroids) is the cause of Addison disease, also called primary adrenal insufficiency (PAI). Today, up to 80% of Addison disease cases are diagnosed as autoimmune Addison disease (AAD), which is caused by an autoimmune response to adrenal tissues disrupting adrenal function. Disruption of adrenal function causes impaired metabolic processes that require normal steroid hormone levels, causing signs and symptoms throughout the body. There is evidence that both humoral and CD4 T_H1-driven CD8 T-cell–mediated immune mechanisms are directed at the adrenal cortex in AAD. There is also evidence that the autoimmune response is associated with autoimmune destruction of other endocrine glands as well, such as the pancreas and thyroid, conditions collectively referred to as autoimmune polyendocrine syndromes (APS). In up to 80% of patients with AAD, antibodies are produced to three enzymes involved in steroid synthesis: 21-hydroxylase (21-OH), 17α-hydroxylase, and cholesterol side-chain–cleaving enzyme. The most common autoantibody found in AAD is to 21-OH, and antibodies to any of the key enzymes for steroid production are diagnostic for AAD. The adrenal cortex cells are targeted, destroyed, and replaced with fibrous tissue by immune-mediated inflammation. In some patients, at least 90% of the adrenal cortex is destroyed before symptoms become diagnostic.

Symptoms of AAD include weakness, nausea, decreased appetite, weight loss, hyperpigmentation, hyperkalemia (elevated blood potassium levels), hyponatremia (decreased blood sodium levels), hypoglycemia (decreased levels of blood sugar), hypotension (decreased blood pressure), anemia, lymphocytosis (decreased levels of white blood cells), and fatigue. Under extreme stress, such as surgery, accidental trauma, or infection, patients with AAD may experience an adrenal crisis that causes the patient to vomit, experience abdominal pain, back or leg cramps, and even severe hypotension leading to shock.

Whereas organ-specific autoimmune diseases target specific organs or tissues, systemic autoimmune diseases are more generalized, targeting multiple organs or tissues throughout the body. Examples of systemic autoimmune diseases include multiple sclerosis, myasthenia gravis, psoriasis, rheumatoid arthritis, and systemic lupus erythematosus.

Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune central nervous system disease that affects the brain and spinal cord. Lesions in multiple locations within the central nervous system are a hallmark of multiple sclerosis and are caused by infiltration of immune cells across the blood-brain barrier. The immune cells include T cells that promote inflammation, demyelination, and neuron degeneration, all of which disrupt neuronal signaling. Symptoms of MS include visual disturbances; muscle weakness; difficulty with coordination and balance; sensations such as numbness, prickling, or “pins and needles”; and cognitive and memory problems.

Myasthenia Gravis

Autoantibodies directed against acetylcholine receptors (AChRs) in the synaptic cleft of neuromuscular junctions lead to myasthenia gravis. Anti-AChR antibodies are high-affinity IgGs and their synthesis requires activated CD4 T cells to interact with and stimulate B cells. Once produced, the anti-AChR antibodies affect neuromuscular transmission by at least three mechanisms:

• Complement binding and activation at the neuromuscular junction
• Accelerated AChR endocytosis of molecules cross-linked by antibodies
• Functional AChR blocking, which prevents normal acetylcholine attachment to, and activation of, AChR

Regardless of the mechanism, the effect of anti-AChR is extreme muscle weakness and potentially death through respiratory arrest in severe cases.

Psoriasis

Psoriasis is a skin disease that causes itchy or sore patches of thick, red skin with silvery scales on elbows, knees, scalp, back, face, palms, feet, and sometimes other areas. Some individuals with psoriasis also get a form of arthritis called psoriatic arthritis, in which the joints can become inflamed. Psoriasis results from the complex interplay between keratinocytes, dendritic cells, and T cells, and the cytokines produced by these various cells. In a process called cell turnover, skin cells that grow deep in the skin rise to the surface. Normally, this process takes a month. In psoriasis, as a result of cytokine activation, cell turnover happens in just a few days. The thick inflamed patches of skin that are characteristic of psoriasis develop because the skin cells rise too fast.

Rheumatoid Arthritis

The most common chronic inflammatory joint disease is rheumatoid arthritis (RA) and it is still a major medical challenge because of unsolved questions related to the environmental and genetic causes of the disease. RA involves type III hypersensitivity reactions and the activation of CD4 T cells, resulting in chronic release of the inflammatory cytokines IL-1, IL-6, and tumor necrosis factor-α (TNF-α). The activated CD4 T cells also stimulate the production of rheumatoid factor (RF) antibodies and anticyclic citrullinated peptide antibodies (anti-CCP) that form immune complexes. Increased levels of acute-phase proteins, such as C-reactive protein (CRP), are also produced as part of the inflammatory process and participate in complement fixation with the antibodies on the immune complexes. The formation of immune complexes and reaction to the immune factors cause an inflammatory process in joints, particularly in the hands, feet, and legs. Diagnosis of RA is based on elevated levels of RF, anti-CCP, quantitative CRP, and the erythrocyte sedimentation rate (ESR) (modified Westergren). In addition, radiographs, ultrasound, or magnetic resonance imaging scans can identify joint damage, such as erosions, a loss of bone within the joint, and narrowing of joint space.

Systemic Lupus Erythematosus

The damage and pathology of systemic lupus erythematosus (SLE) is caused by type III hypersensitivity reactions. Autoantibodies produced in SLE are directed against nuclear and cytoplasmic proteins. Anti-nuclear antibodies (ANAs) are present in more than 95% of patients with SLE, with additional autoantibodies including anti-double–stranded DNA (ds-DNA) and anti-Sm antibodies (antibodies to small nuclear ribonucleoprotein). Anti-ds-DNA and anti-Sm antibodies are unique to patients with SLE; thus, their presence is included in the classification criteria of SLE. Cellular interaction with autoantibodies leads to nuclear and cellular destruction, with components released after cell death leading to the formation of immune complexes.

Because autoantibodies in SLE can target a wide variety of cells, symptoms of SLE can occur in many body locations. However, the most common symptoms include fatigue, fever with no other cause, hair loss, and a sunlight-sensitive "butterfly" or wolf-mask (lupus) rash that is found in about 50% of people with SLE. The rash is most often seen over the cheeks and bridge of the nose, but can be widespread. Other symptoms may appear depending on affected areas. The joints may be affected, leading to arthritis of the fingers, hands, wrists, and knees. Effects on the brain and nervous system can lead to headaches, numbness, tingling, seizures, vision problems, and personality changes. There may also be abdominal pain, nausea, vomiting, arrhythmias, shortness of breath, and blood in the sputum. Effects on the skin can lead to additional areas of skin lesions, and vasoconstriction can cause color changes in the fingers when they are cold (Raynaud phenomenon). Effects on the kidneys can lead to edema in the legs and weight gain. A diagnosis of SLE depends on identification of four of 11 of the most common symptoms and confirmed production of an array of autoantibodies unique to SLE. A positive test for ANAs alone is not diagnostic.

Some autoimmune diseases target specific organs or tissue, while others attack multiple tissue or organ systems throughout the body. Here’s what you need to know about five common conditions. 

Lupus 

A chronic (long-lasting) disorder that causes damage to multiple areas of the body.

What’s affected?

Connective tissue in almost any organ or system of the body.

Who can develop it?

Anyone can develop lupus, but it’s most common in:

• Women 
• People between ages 15 and 45
• African Americans, Native Americans, Native Alaskans, Native Hawaiians, and people of Asian descent
• People who have a family member with lupus or another autoimmune disease

What are the symptoms? 

Common symptoms include: 

• Joint pain or swelling 
• Muscle pain and weakness
• Fever 
• Sun sensitivity
• Red rash (such as “butterfly” rash on the nose and cheeks)
• Swollen lymph nodes 
• Fatigue and general malaise (feeling unwell)
• Sores in the nose and mouth

Other symptoms depend on what parts of the body are affected.

Sjögren’s syndrome

A chronic disorder that causes damage to the glands that create moisture and lubrication (particularly tears and saliva).

What’s affected?

Primarily the eyes and mouth, but it can also affect parts of the body like joints, lungs, and muscles. 

Who can develop it?

Most people with Sjögren’s syndrome are women. It is usually diagnosed after age 40. 

What are the symptoms? 

The most common symptoms are dry eyes and mouth, pain in the joints or muscles, and severe fatigue. Other symptoms may include itchy skin, nasal irritation and nosebleeds, and dry cough.

Rheumatoid arthritis (RA)

A chronic disorder that causes damage to joint tissue.

What’s affected?

Primarily targets the body’s joints (usually on both sides of the body) and the tissues around them. It may also affect other systems of the body such as skin, eyes, lungs, heart, and blood vessels. 

Who can develop it?

RA is more common in women than in men. The risk increases as you get older, but you can develop it at any age.   

What are the symptoms? 

The most common symptoms are swelling, pain, and stiffness in joints (typically in the wrists, hands, feet, spine, knees, or jaw). 

RA causes swelling in the lining of the joints, which can lead to harmful structural changes in the bones and joints over time. 

Psoriasis

A chronic disorder in which an overactive immune system causes skin cells to multiply and rise to the surface of the skin too quickly.

What’s affected?

Skin.

Who can develop it?

Anyone can develop psoriasis, but adults have it more often than children.

What are the symptoms? 

Itchy or sore patches of thick, red, scaling on the skin.

Psoriatic arthritis

A chronic autoimmune form of arthritis that affects the skin and joints. It can worsen over time. 

What’s affected?

Skin and joints. 

Who can develop it?

Psoriatic arthritis is more common in adults than in children. Most people who develop psoriatic arthritis already have psoriasis. It can be triggered by stress, physical trauma, or infections. 

What are the symptoms? 

Common symptoms include:

• Pain, stiffness, and swelling in joints (on one or both sides of the body)
• Pain and swelling in other parts of the body such as hands, feet, and low back
• Itchy or sore patches of thick, red, scaling on the skin

Autoimmune diseases tend to run in families. You’re more likely to develop one if you:

• Have a family member with an autoimmune disease
• Are already diagnosed with one or more autoimmune diseases

Also, your racial and ethnic background, assigned sex, and age may make you more or less likely to develop certain autoimmune diseases. For example, many kinds of autoimmune diseases such as lupus, scleroderma, and Sjögren’s syndrome are far more common among women than among men.  

Because specific viruses or environmental conditions may trigger autoimmune diseases, the risk of certain autoimmune diseases may be higher in people who are more likely to be exposed to those triggers. 

While scientists and doctors aren’t exactly sure what causes autoimmune disease, they are likely triggered by interactions between genes, the immune system, and the environment. 

There’s still a lot to learn about these relationships, but experts think that even if a person with certain genes or certain combinations of genes is at risk of an autoimmune disease, they probably won’t develop the condition without something in their environment triggering it or turning it on. Environmental triggers may include:

• Infection (from a virus or bacteria)
• Stress
• Dietary components (such as gluten or dairy)
• Contaminants in food (such as mercury in fish)
• Environmental pollutants (such as certain pesticides) 

Autoimmune diseases can affect different parts of the body. Their symptoms can be similar and even vague, and specific symptoms may not even look the same for every condition. Many of the most common ones―such as fatigue, joint pain, and muscle pain―could also be symptoms of other conditions.

Most autoimmune diseases cause inflammation, so people with autoimmune diseases often experience heat, pain, or swelling (which are all signs of inflammation) in the part of the body that’s affected. Other common symptoms include: 

• Fatigue
• Low-grade fever
• Losing or gaining weight 
• Dizziness
• Swelling or pain in muscles or joints
• Difficulty thinking clearly or paying attention
• Rashes
• Digestive problems (such as bloating, cramping, diarrhea, or constipation)

People with autoimmune conditions often experience symptoms in cycles, and symptoms can change over time. Even with treatment, there may be periods of time where symptoms worsen or new symptoms appear (flares), followed by periods of remission where they disappear or become less intense. 

For many people with autoimmune symptoms, getting an accurate diagnosis can be difficult, time-consuming, and stressful.

To diagnose an autoimmune disease, a health care provider will do a physical exam and ask you about your symptoms, your medical history, and your family’s health history, including if others in your family have been diagnosed with one or more autoimmune diseases. Depending on your symptoms and background, they may recommend blood tests, imaging, or other diagnostic tests.  

There’s no cure for most autoimmune diseases, but there are treatments to help people who have them address and manage their symptoms. Treatments vary depending on the disease and how the individual is affected. 

In addition to your primary care provider, you may work with one or more specialists, including: 

• Immunologists (for immune system disorders)
• Rheumatologists (for rheumatic diseases such as arthritis and other inflammatory disorders)  
• Endocrinologists (for glands and hormones)
• Hematologists (for blood disorders)
• Neurologists (for nervous system disorders)
• Cardiologists (for diseases of the heart and blood vessels)
• Gastroenterologists (for the gastrointestinal tract)
• Dermatologists (for skin diseases)

You and your health care team can work together to create a treatment plan that works best for you, your lifestyle, and your symptoms with the fewest possible side effects. This could include pharmacological (drug-based) medicines that:

• Reduce pain (such as nonsteroidal anti-inflammatory drugs)
• Control inflammation (such as corticosteroids)
• Inhibit the immune response (such as immunosuppressants) 

In addition to these treatments, there may be certain activities, diets, and long-term lifestyle changes that can help you manage your symptoms and feel better.