The 14 Most Common Autoimmune Diseases—and Who’s Most at Risk for Each

Most common autoimmune diseases by body system

Endocrine System

Hashimoto’s thyroiditis (autoimmune hypothyroidism)

In Hashimoto’s thyroiditis, the immune system mistakenly attacks the thyroid gland, slowing down hormone production and metabolism. Common symptoms include fatigue, weight gain, constipation, dry skin, and feeling unusually cold. Another potential symptom is a painless swelling in the neck called a goiter.

Hashimoto’s thyroiditis is the leading cause of hypothyroidism (when the body produces an insufficient amount of the thyroid hormone) “in countries with widely available iodized salt and other iodine-enriched foods,” says the Cleveland Clinic, affecting five out of every 100 Americans. It is far more common in women, often appearing in midlife. With thyroid hormone replacement therapy, most people can keep their levels balanced and feel well again.

Graves’ disease (autoimmune hyperthyroidism)

Graves’ disease causes the immune system to overstimulate the thyroid, making it produce too much hormone. The result is a revved-up metabolism that can cause weight loss, rapid heartbeat, heat intolerance, anxiety, and tremors. Some people also experience eye changes known as thyroid eye disease. Graves’ is the most common cause of hyperthyroidism, typically affecting women in early to mid-adulthood. Yale Medicine estimates that 1% of the U.S. population has Graves’ disease. Treatment options include antithyroid medications, radioactive iodine therapy, or surgery.

Type 1 diabetes

The American Diabetes Association reports that 2 million Americans have type 1 diabetes. This condition develops when the immune system destroys the insulin-producing beta cells in the pancreas, leaving the body unable to properly regulate blood sugar. Early signs include frequent urination, extreme thirst, fatigue, and unexplained weight loss.

Type 1 diabetes usually begins in childhood or adolescence, though adults can develop it too. It requires lifelong insulin therapy, but modern tools like continuous glucose monitors and insulin pumps have made management easier and help many people lead long, healthy lives.

Musculoskeletal System

Rheumatoid arthritis (RA)

Rheumatoid arthritis occurs when the immune system attacks the lining of the joints, often in the hands, wrists, and feet. It causes pain, swelling, stiffness, and fatigue, which can worsen over time if untreated. The condition—affecting 1.5 million Americans, per Yale Medicine—most often appears in middle adulthood and affects women three times more often than men. With early diagnosis and modern treatments—especially biologic medications that calm the immune response—many people achieve remission and are able to stay active.

Systemic lupus erythematosus (lupus)

Lupus is a systemic autoimmune disease that can affect the skin, joints, kidneys, heart, and other organs. Symptoms often include fatigue, joint pain, fever, hair loss, and skin rashes, particularly the classic “butterfly” rash across the cheeks. The Lupus Foundation of America estimates that 1.5 million Americans have lupus, which primarily affects women of childbearing age, especially women of color. With ongoing care and medications that control inflammation, most people with lupus can manage flares and prevent long-term complications.

Gastrointestinal system

Celiac disease

Celiac disease is triggered by eating gluten, a protein found in wheat, barley, and rye. In people with the condition, gluten prompts an immune attack on the lining of the small intestine, leading to symptoms like bloating, diarrhea, abdominal pain, and fatigue. Some people experience subtler signs, such as anemia or osteoporosis, due to poor nutrient absorption. It can occur at any age, and the National Institutes of Health says many people who have it are not currently diagnosed. However, experts believe as many as 2 million Americans have this disease. The only effective treatment is a strict gluten-free diet, which allows the intestine to heal.

Crohn’s disease

Crohn’s disease—affecting an estimated 750,000 people in the U.S., per the Cleveland Clinic—causes inflammation anywhere along the digestive tract, most often in the small intestine or colon. Common symptoms include cramping, persistent diarrhea, weight loss, and fatigue. The condition usually begins in young adulthood and tends to cycle between periods of flare-ups and remission. Treatment focuses on reducing inflammation and maintaining remission through a combination of medication, nutrition support, and lifestyle management.

Ulcerative colitis

Ulcerative colitis is a chronic inflammatory condition limited to the colon (large intestine). Between 600,000 to 900,000 Americans likely have this condition, according to the National Institutes of Health. It typically causes bloody diarrhea, abdominal pain, and an urgent need to use the bathroom. Like Crohn’s, it tends to come and go in cycles, and long-term inflammation can increase the risk of colon cancer, so regular screening is important. Most people manage symptoms with medication, though in severe cases, surgery to remove the colon can be curative.

Nervous system

Multiple sclerosis (MS)

Nearly 1 million people in the U.S. have multiple sclerosis, also known as MS, says the National Multiple Sclerosis Society. In multiple sclerosis, the immune system attacks the myelin sheath—the protective covering of nerve fibers in the brain, spinal cord, and optic nerves—which disrupts communication between the brain and body. Symptoms often include vision problems, numbness or weakness on one side, imbalance, dizziness, and severe fatigue. MS usually begins in young adulthood and affects women more often than men. Modern disease-modifying therapies, many of which target specific immune cells, have transformed treatment, reducing relapses and slowing disease progression for many people.

Myasthenia gravis (MG)

Myasthenia gravis, commonly referred to as MG, occurs when antibodies interfere with communication between nerves and muscles, leading to muscle weakness that worsens with activity and improves with rest. It often begins with drooping eyelids or double vision and may also affect speech, swallowing, or breathing. MG can appear at any age but is most common in young women and older men. With treatments that strengthen nerve-muscle signaling or calm the immune attack, most people manage symptoms well and lead active lives. The American Brain Foundation reports that 36,000 to 60,000 people in the U.S. have this disease.

Integumentary system (skin and hair)

Psoriasis

Psoriasis speeds up the skin’s growth cycle, causing thick, scaly patches that may itch, crack, or hurt—often appearing on the elbows, knees, scalp, or lower back. About 3% of adults in the U.S. are affected, according to the National Psoriasis Foundation, and nearly a third also develop psoriatic arthritis, which inflames the joints. Severity can vary widely, but modern targeted therapies have made it possible for many to achieve clear or nearly clear skin.

Sjögren’s syndrome

Sjögren’s syndrome targets the body’s moisture-producing glands, leading to dry eyes, dry mouth, fatigue, and joint pain. It can also affect the skin, lungs, and kidneys, and it often appears alongside other autoimmune conditions such as rheumatoid arthritis or lupus. The Sjögren’s Association estimates that as many as 4 million Americans experience this condition. It mostly occurs in women in midlife, and treatment focuses on protecting the eyes and mouth and calming the immune system when internal organs are involved.

Vitiligo

In vitiligo, immune cells destroy the melanocytes that give skin its color, resulting in white patches—commonly on the face, hands, and around body openings. It can affect men and women of all skin tones—and research published in the Journal of American Medical Association’s Dermatology in 2021 concluded that while as many as 2.8 million U.S. adults may have vitiligo, approximately 40% of those individuals may be undiagnosed. Although treatments such as topical creams or light therapy can help restore pigment, their results are often inconsistent, and since vitiligo isn’t painful or harmful, many people choose not to treat it.

Alopecia areata

Alopecia areata happens when the immune system attacks the hair follicles, causing sudden, patchy hair loss on the scalp or other areas such as the eyebrows or beard. It can occur at any age and may come and go unpredictably. The National Alopecia Areata Foundation reports that 700,000 Americans currently have this condition. Injections and new immune-targeted therapies can encourage regrowth and reduce future flare-ups.

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