Top 8 Autoimmune Illnesses and Diseases

When you have an autoimmune disease, your immune system — your body’s best defense — mistakenly turns against you. It gets confused and starts attacking healthy cells and tissues as if they were harmful bacteria or viruses. Several specialists, including Suman Khicher, MD, a rheumatologist at UnityPoint Health, explain why this happens, what to do about it, the most common autoimmune diseases and how they're diagnosed and treated.

What is an Autoimmune Disease?

There are more than 80 different autoimmune diseases, and they can affect any part of your body. Some target specific organs, while others affect multiple parts of the body at once. Because your immune system is misidentifying healthy cells as threats, it triggers inflammation.

Chronic inflammation can lead to tissue damage and swelling. Understanding the early signs of an autoimmune disease and knowing the different types can help you, and your doctor, create a plan to get you feeling better, faster.

What are the Symptoms of Autoimmune Diseases?

Symptoms of autoimmune diseases vary, but these general indicators of inflammation and tissue damage may mean your body is working against itself:

• Digestive problems
• Dry eyes or mouth
• Fatigue
• Hair loss
• Joint pain or stiffness
• Low fever
• Muscle weakness
• Numbness or tingling
• Skin rashes
• Unexplained weight loss
• Weight gain

What Causes Autoimmune Diseases?

Autoimmune diseases usually stem from a mix of your genetics and environmental factors. Factors that may increase your risk for an autoimmune disease include:

• Chemical exposures (like silica dust, a natural mineral found in the earth)
• Chronic stress
• Family history
• Genetics
• Gut microbiome imbalances
• Hormonal changes
• Obesity
• Smoking
• Viral infections (like Epstein-Barr virus and COVID-19)
• Vitamin D deficiency

“There’s no guaranteed way to prevent autoimmune diseases,” Dr. Khicher says, “but a healthy lifestyle, diet and habits may help reduce risk.”

Are Women More Likely to Get Autoimmune Diseases Than Men?

Yes, women are about three times more likely to develop an autoimmune disease than men, but the exact reasoning isn't fully understood.

"Women have two X chromosomes while men have one, and the X chromosome contains many genes that control immune function," Dr. Khicher says.

“In women with autoimmune diseases, the process that normally ‘turns off’ one X chromosome doesn't work properly, allowing immune genes to become overactive. Estrogen also plays a complex role. It can reduce inflammation, but it also increases certain immune cells and antibodies that may contribute to autoimmune conditions." 

How are Autoimmune Diseases Diagnosed?

To find out if you have an autoimmune disease, doctors use a combination of physical exams and medical tests. Since early symptoms of autoimmune diseases may be mild and share similar signs of other conditions, making a specific diagnosis is a process of elimination, taking time and multiple tests.

An autoimmune disease test may include:

• Biopsies
• Blood count tests to detect antibodies and inflammation
• Imaging tests like X-rays or MRI scans
• Urine tests

Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease where the immune system attacks the lining of the joints. This causes inflammation, pain and swelling. RA typically starts in smaller joints, like the hands and feet, before spreading to other joints in the body.

A telltale sign of RA is morning stiffness. Many people wake up feeling like their joints are locked. You may need to move around for several hours before your joints feel loose again. Extreme fatigue that doesn’t improve with rest is also common.

RA tends to follow a pattern of flare ups:

• Symptoms suddenly worsen, and simple tasks like opening a jar or buttoning a shirt become difficult.
• Between flares, symptoms may disappear altogether.

Rheumatoid Arthritis Treatments

Disease-modifying antirheumatic drugs (DMARDs) are rheumatoid arthritis medications that can slow or stop the disease process. They’re usually paired with physical therapy, exercise programs and lifestyle modifications, like quitting smoking.

Psoriasis

Psoriasis is a condition where the immune system speeds up skin cell growth. Normally, skin cells grow and fall off over about a month. With psoriasis, this happens in just a few days, causing cells to build up on the surface of the skin. The result is red, flaky patches on the skin that are itchy and painful.

They’re called plaques and are the most recognizable symptom of psoriasis. They most commonly appear on the scalp, elbows and knees. Although the patches may look concerning, they can’t be passed from person to person.

"Psoriasis is not contagious,” Rachel Koziczkowski, MD, a dermatologist at UnityPoint Health says.

“It's inflammation inside the body that appears on the surface. Patients often feel embarrassment or anxiety since other people may assume their skin patches are transmissible.”

Eczema vs Psoriasis

People sometimes confuse psoriasis with eczema. However, there’s a difference in how these two conditions appear. Psoriasis patches are white and flaky with a very defined border between plaques and normal skin. Eczema looks like red, itchy rashes with no clear border.

Type 1 Diabetes

Type 1 diabetes is caused by the immune system attacking cells in the pancreas that make insulin. Without insulin, the body can’t turn sugar into energy. Type 1 diabetes can develop in anyone, but symptoms typically start appearing when you’re young.

The most common early symptoms of type 1 diabetes include:

• Intense thirst
• Unexpected weight loss

Managing type 1 diabetes requires significant lifestyle changes. People with the condition need to monitor their blood sugar and take insulin every day. Blood sugar levels can shift after food, exercise or stress. While there isn’t currently a cure for Type 1 diabetes, treatments are effective and people with the condition can live full, normal lives.

Graves’ Disease

Graves’ disease happens when the immune system overstimulates the thyroid gland. This leads to the release of too many thyroid hormones into your bloodstream, a condition called hyperthyroidism.

When the thyroid is in overdrive, the rest of the body feels it. This causes symptoms of hyperthyroidism such as:

• Anxiety
• Rapid heart rate
• Shaky hands
• Unexplained weight loss

Some people also develop a goiter — a visually enlarged thyroid on the neck. A unique symptom that sets Graves’ disease apart from other thyroid conditions is Graves’ ophthalmopathy. This is where the eyes bulge forward and become red, swollen and sensitive to light.

Hashimoto’s Disease

Hashimoto’s disease is a condition where the immune system gradually damages the thyroid gland. Over time, this makes it harder for the thyroid to make enough hormones, leading to hypothyroidism — the opposite issue from Graves’ disease.

Because the thyroid is involved in so many bodily functions, an underactive thyroid, or hypothyroidism, makes everything feel sluggish. Common symptoms of hypothyroidism include:

• Dry skin
• Fatigue
• Hair loss
• Sensitivity to cold
• Unexplained weight gain

Some people with Hashimoto’s disease experience depression, too. Additionally, as the thyroid works hard to keep up, a goiter may develop.

“At the onset of Hashimoto’s disease, symptoms might actually mimic an overactive thyroid because the thyroid is inflamed,” Kenneth Ligaray, MD, endocrinologist at UnityPoint Health, says.

Many people live with Hashimoto’s for years before getting a diagnosis because of how slowly it develops. Symptoms can be brushed off as signs of aging or stress at first, but over time, they’re hard to ignore.

Crohn’s Disease

Crohn’s disease is an inflammatory bowel disease where the immune system attacks the digestive tract lining. Unlike other digestive conditions, Crohn’s can affect any part of the digestive tract – from the mouth to the rectum. Most commonly, it affects the area where the small and large intestines connect, called the ileocecal region.

Crohn’s symptoms initially present as:

• Constant urge to have a bowel movement, even after just going
• Nausea
• Persistent diarrhea
• Stomach cramping
• Unexpected weight loss

Although symptoms may begin as mild, they can become more severe as the disease progresses. Unlike other autoimmune conditions, Crohn's disease affects men and women equally.

Crohn’s flare-ups are unpredictable and can make everyday activities — such as working or socializing — difficult.

“Many people with Crohn’s feel the need to constantly know where bathrooms are and often structure their daily lives around managing symptoms,” Jess Bailey, ARNP, at UnityPoint Health says. “This ongoing stress, disruption and loss of normal routine can lead to feelings of isolation and reduced quality of life, which increases the risk of depression.”

Crohn's disease requires long-term monitoring and management. With proper care and staying in good health, people affected by the condition can live an active and otherwise healthy lifestyle.

Multiple Sclerosis

Multiple sclerosis (MS) occurs when the immune system attacks the nerves that control movement, slowing down nerve signals or stopping them altogether.

“The nerve is like an electrical wire,” Calvin Hansen, MD, neurologist at UnityPoint Health, says.

“Just like electrical wires in the wall, you need insulation to help the electrical activity travel through. That insulation on a nerve is called myelin — that's what MS attacks in the brain and spinal cord.”

MS affects everyone differently, which can make it a frustrating condition to understand. Most commonly, the earliest symptoms are weakness or numbness in the limbs and vision loss in one eye. Unlike a stroke, where symptoms appear suddenly, MS symptoms develop gradually over days or weeks.

There are two types of MS:

• Progressive MS: A less common type where symptoms gradually worsen over time without periods of improvement.

• Relapsing-remitting MS: The most common type, where symptoms flare up and then improve, followed by new symptoms that may appear months or years later.

Lupus (systemic lupus erythematosus)

Systemic lupus erythematosus, or lupus, happens when the immune system attacks the body’s own healthy tissues and organs. While some autoimmune diseases target one area or organ, lupus can involve multiple parts of the body at the same time. Lupus primarily impacts women and most commonly affects the skin, joints, kidneys, lungs, heart and blood cells.

Lupus is known as “the great imitator,” because its symptoms mimic many other diseases. No two people with lupus have the same experience, but the most common symptoms include:

• Butterfly rash
• Fatigue
• Hair loss
• Mouth ulcers

Living with an Autoimmune Disease

Autoimmune diseases can feel overwhelming, but learning about your condition is an important first step in managing it. Whether you’re noticing early symptoms like fatigue or joint pain, or have already received a diagnosis, guidance from healthcare professionals makes a major difference in how you feel and your quality of life.

Your primary care provider is a good place to start. They can help evaluate your symptoms and discuss next steps for care. With proper support and treatment, many people with autoimmune diseases live full, active lives.