Connective Tissue Diseases

IWBCA
Feb 16
14 min read

Updated: Feb 19

Connective tissue diseases are a broad group of conditions that affect the tissues that support, connect, and protect every structure in the body. They include autoimmune, genetic, and cancer-related disorders that can cause widespread symptoms and organ involvement.

Overview

What are connective tissue diseases?

Connective tissues form the internal “scaffolding” that supports your organs and body structures. They surround and stabilize your joints, hold muscle fibers together, protect and insulate your nerves, and include body fat, bones, cartilage, fascia, ligaments, skin, and tendons. A connective tissue disease is an umbrella term for a range of conditions that damage connective tissues. Because connective tissues are present nearly everywhere in the body, connective tissue diseases can involve one tissue type in many locations, many tissues at once, or multiple organs and systems at the same time. There are more than 200 known connective tissue disorders, which are broadly grouped into autoimmune diseases, genetic disorders, and cancers known as sarcomas.

Symptoms

What symptoms are common in connective tissue diseases?

Common symptoms of connective tissue diseases include musculoskeletal pain, stiffness, and fatigue. Some people notice joint swelling, muscle weakness, or changes in their skin, such as thickening, tightening, rashes, or easy bruising. Because connective tissues span the entire body, symptoms can also involve the lungs, heart, kidneys, eyes, blood vessels, digestive tract, or nervous system. The pattern and severity of symptoms vary widely depending on the specific condition and which connective tissues and organs are involved.

Types

What are the main types of connective tissue disease?

Autoimmune Connective Tissue Diseases: Autoimmune connective tissue diseases occur when the immune system mistakenly attacks the body’s own connective tissues, causing chronic inflammation. This persistent inflammation leads to pain, swelling, and, over time, permanent structural damage to joints, skin, muscles, blood vessels, or internal organs. These conditions can remain localized to a single region, such as the joints, or become systemic, affecting multiple organs throughout the body.
Genetic Connective Tissue Disorders: Genetic connective tissue disorders result from inherited changes in genes that regulate the formation or maintenance of connective tissues. These gene changes often affect collagen, elastin, or other key structural proteins. As a result, tissues may become unusually fragile, too stretchy, or fail to provide normal support. People with these conditions may experience skeletal abnormalities, joint instability, skin fragility, and complications involving major organs and blood vessels.
Connective Tissue Cancers (Sarcomas): Sarcomas are rare cancers that develop from connective tissues such as bone, cartilage, fat, or muscle. They differ from autoimmune and genetic connective tissue diseases because they involve uncontrolled proliferation of abnormal cells rather than chronic inflammation or inherited structural weakness. Treatment usually focuses on removing or shrinking the tumor and preventing spread, using surgery, radiation, chemotherapy, or targeted therapies.

Autoimmune Connective Tissue Diseases

Which autoimmune connective tissue diseases are most common?

Rheumatoid Arthritis: Rheumatoid arthritis is an autoimmune disease that primarily targets the lining of the joints, causing pain, swelling, and stiffness, especially in the hands, wrists, and feet. Over time, persistent inflammation can damage cartilage and bone, leading to joint deformity and loss of function. In some individuals, inflammation extends beyond the joints to affect blood vessels, the eyes, the lungs, or other organs.

Relapsing Polychondritis: Relapsing polychondritis causes recurrent inflammation and gradual cartilage degeneration, most often in the ears, nose, and airways. Flare-ups can cause pain, redness, and tenderness in these areas and may alter the shape of the ears or nose over time. When the cartilage of the windpipe or bronchi is involved, breathing can become difficult, and inflammation can also affect the eyes, heart, or blood vessels.

Myositis: Myositis is a group of autoimmune diseases characterized by inflammation and weakness of skeletal muscles. People with myositis often notice difficulty climbing stairs, lifting objects, or rising from a seated position. Certain forms also inflame the skin, causing distinctive rashes, and may involve the lungs, heart, or the muscles used for swallowing. Long-standing inflammation can lead to muscle wasting and reduced strength.

Sjögren’s Syndrome: Sjögren’s syndrome primarily affects the moisture-producing glands, leading to dry eyes, dry mouth, and dryness in the nose, throat, and other mucous membranes. People may experience gritty, irritated eyes; difficulty swallowing dry foods; dental decay; hoarseness; or a chronic cough. In some cases, the disease also affects joints, nerves, lungs, kidneys, or blood vessels and can cause fatigue and widespread pain.

Lupus: Lupus, often called systemic lupus erythematosus (SLE), is an autoimmune disease that can cause inflammation in almost any connective tissue. It frequently involves the skin and joints and may affect vital organs, including the kidneys, heart, lungs, and brain. Symptoms vary, but can include joint pain, rashes, extreme fatigue, mouth sores, chest discomfort, and kidney or neurological problems. Disease activity often fluctuates with periods of flares and remission.

Scleroderma: Scleroderma is a group of conditions characterized by the overproduction and accumulation of collagen in the skin and internal organs. The skin may become thick, tight, and shiny, particularly on the hands, face, or limbs. When internal organs are involved, scleroderma can affect the digestive tract, lungs, heart, or kidneys, leading to reflux, difficulty swallowing, shortness of breath, high blood pressure in the lungs, or kidney problems. Raynaud’s phenomenon, where fingers and toes turn white or blue in response to cold, is common.

Mixed Connective Tissue Disease: Mixed connective tissue disease describes a condition in which a person has overlapping features of several autoimmune connective tissue diseases, most often including lupus, scleroderma, and polymyositis. People may experience a combination of joint pain, muscle weakness, Raynaud’s phenomenon, skin changes, and organ involvement. Laboratory testing often shows specific autoantibodies that help support the diagnosis.

Undifferentiated Connective Tissue Disease: Undifferentiated connective tissue disease is diagnosed when a person has symptoms and blood test findings suggestive of an autoimmune connective tissue disease, but the pattern does not fit the established criteria for any single condition. Symptoms may include joint pain, Raynaud’s phenomenon, fatigue, or mild skin changes. Some individuals remain in this undifferentiated category, whereas others progress to a more clearly defined autoimmune disease.

Genetic Connective Tissue Disorders

What are the main types of genetic connective tissue disorders?

Marfan Syndrome: Marfan syndrome affects connective tissue components that provide elasticity and support, particularly in the skeleton, eyes, and cardiovascular system. People with Marfan syndrome often have tall stature, long limbs and fingers, flexible joints, and a narrow chest. The condition can also weaken the walls of the aorta, the main artery leaving the heart, increasing the risk of enlargement or tearing if left unmonitored and untreated.

Ehlers-Danlos Syndrome: Ehlers-Danlos syndrome (EDS) represents a group of disorders that weaken collagen, a key structural protein in skin, joints, and blood vessels. Many people with Ehlers-Danlos syndrome have unusually flexible joints, stretchy or fragile skin, and a tendency to bruise or scar easily. Certain types also affect blood vessels and internal organs, which can increase the risk of serious complications such as arterial rupture or organ rupture.

Osteogenesis Imperfecta: Osteogenesis imperfecta is a genetic condition that reduces the quantity or quality of type I collagen, which is essential for bone strength, ligaments, and teeth. People with osteogenesis imperfecta often have bones that fracture easily, sometimes with minimal trauma. They may also have loose joints, short stature, dental problems, and hearing loss. Symptom severity ranges from mild to life-limiting, depending on the specific genetic change.
Stickler Syndrome: Stickler syndrome affects collagen in cartilage and in the gel-like vitreous humor of the eye. It can present with nearsightedness, retinal problems, and an increased risk of retinal detachment. Many people also develop hearing loss, cleft palate, facial differences, and early-onset arthritis in weight-bearing joints. Care usually involves coordinated monitoring by ophthalmology, audiology, orthopedics, and other specialists.
Epidermolysis Bullosa: Epidermolysis bullosa is a group of inherited conditions that make the skin and, in some cases, the mucous membranes extremely fragile. Even minor friction or trauma can cause painful blisters and open wounds. The mouth, throat, and airway may also be affected, making eating and breathing more difficult. Repeated skin injury and scarring can lead to chronic pain, infections, nutritional problems, and, in some forms, an increased risk of skin cancer.
Loeys-Dietz Syndrome: Loeys-Dietz syndrome involves genetic changes that disrupt signaling pathways guiding connective tissue development. It often causes aortic and the arterial enlargement and fragility, increasing the risk of aneurysm or dissection at a young age. People may also have skeletal differences, such as scoliosis or chest wall abnormalities, joint laxity, and distinctive facial features. Close imaging surveillance and timely medical or surgical treatment of vascular disorders are essential.

Management and Monitoring

How are genetic connective tissue disorders managed over time?

Genetic connective tissue disorders cannot be corrected at their source because the underlying gene mutation is present from birth; however, careful management can address symptoms, reduce complications, and improve quality of life. Treatment plans are tailored to the specific condition and may include physical therapy, bracing or surgery for skeletal problems, medications to protect the heart and blood vessels, wound care and infection prevention for fragile skin, and regular eye, hearing, and dental evaluations. Lifelong monitoring with imaging, laboratory testing, and specialist visits helps identify emerging complications early, enabling prompt and safe treatment.

Cancers of the Connective Tissues

What types of cancers can develop in connective tissues?

The primary cancers that begin in connective tissues are called sarcomas. Sarcomas can arise in bones, cartilage, fat, muscles, ligaments, tendons, and the deeper layers of the skin. They can also start in nearby “soft tissues” that are not strictly connective tissue, such as epithelial and endothelial layers that line organs and blood vessels. Sarcomas are uncommon but important because they can grow silently for a long time, may spread to other parts of the body, and often require specialized treatment at high-volume centers.

Osteosarcoma: Osteosarcoma is the most common primary bone cancer. It usually develops in the long bones of the arms or legs, often near the knee or shoulder, and is more frequent in children, adolescents, and young adults. People may notice worsening bone pain, swelling, or limited range of motion near the affected joint. Without treatment, osteosarcoma can weaken the bone enough to cause fractures and can spread to other organs, most often the lungs.
Chondrosarcoma: Chondrosarcoma is a bone cancer that develops from cartilage, the smooth, rubbery tissue that cushions joints and lines the ends of bones. It most often affects adults and can arise in the pelvis, ribs, shoulder girdle, or long bones. Symptoms may include deep, persistent pain, a gradually enlarging mass, or stiffness in the nearby joint. Some chondrosarcomas grow slowly, while others are more aggressive and more likely to spread.
Ewing Sarcoma: Ewing sarcoma is a tumor that can start in bone or, less commonly, in the soft tissues around bone. It typically occurs in children, adolescents, and young adults and often affects the pelvis, long bones, or chest wall. People may experience localized pain and swelling, fever, or general fatigue. Because it can initially resemble infection or injury, imaging and biopsy are often required to confirm the diagnosis.
Fibrosarcoma: Fibrosarcoma arises from fibrous connective tissues such as ligaments and tendons. It may appear as a painless or mildly tender lump that gradually enlarges, usually in the arms, legs, or trunk. As it grows, it can press on nearby nerves, muscles, or blood vessels, causing pain, weakness, or changes in limb function. In some cases, fibrosarcoma can spread to other parts of the body, most often the lungs.
Clear Cell Sarcoma: Clear cell sarcoma typically begins in the tendons, fascia, or muscles of the arms or legs, particularly around the ankles and feet. It may present as a slow-growing lump that can be mistaken for a benign soft tissue mass. Over time, it can become painful or interfere with movement. Clear cell sarcoma tends to spread to nearby lymph nodes and distant sites, making early recognition and specialist care important.
Liposarcoma: Liposarcoma is a cancer that develops from fat cells in deep soft tissues, most commonly in the thigh, behind the knee, or inside the abdomen. It usually presents as a painless, enlarging mass that may only be noticed when it becomes large enough to distort the shape of a limb or abdomen. When liposarcomas grow inside the abdomen, they can press on organs and cause fullness, discomfort, or changes in bowel habits before they are detected.
Dermatofibrosarcoma Protuberans: Dermatofibrosarcoma protuberans is a rare sarcoma that begins in the middle layer of the skin, called the dermis. It often starts as a firm, flat, or slightly raised patch that slowly enlarges over the years and can develop into one or more nodules. Although it is usually slow-growing and less likely to spread to distant organs, it can invade nearby tissues extensively, so wide surgical removal is typically needed.
Myxofibrosarcoma: Myxofibrosarcoma usually starts as a soft lump under the skin, most often in the arms or legs of older adults. The lump may be painless at first, which is why it can be overlooked. Over time, it may grow, become more irregular, or develop multiple nodules. Myxofibrosarcoma can recur locally after removal and, in some cases, can spread to distant sites, so long-term follow-up is important.

Symptoms and Causes

What symptoms and causes are associated with connective tissue diseases and sarcomas?

Musculoskeletal Pain, Weakness, and Stiffness: Many connective tissue diseases cause pain, weakness, and stiffness in muscles, joints, or both. People may describe aching limbs, difficulty with physical tasks, or morning stiffness that lasts longer than expected. Over time, chronic inflammation or structural weakness can make movement more difficult, limit the range of motion, and reduce overall physical stamina.
Systemic Symptoms and Fatigue: Fatigue is a common symptom across many autoimmune and genetic connective tissue diseases. People often feel unusually tired even after adequate rest and may notice low-grade fevers, unintentional weight changes, or a general sense of unwellness. These systemic symptoms reflect the fact that connective tissues and immune activity influence the whole body, not just individual joints or muscles.
Cardiopulmonary Symptoms: Because the lungs, heart, and blood vessels contain and depend on healthy connective tissues, many connective tissue diseases involve the cardiopulmonary system. People may experience shortness of breath, reduced exercise tolerance, chest discomfort, palpitations, or changes in blood pressure. Inflammation or structural weakness in blood vessels can impair circulation and increase the risk of complications such as pulmonary hypertension or vascular rupture.
Bleeding and Blood Vessel Involvement: When blood vessels become inflamed, thickened, or damaged, they may swell and lose their normal strength. This can lead to visible signs such as small red or purple spots on the skin, easy bruising, or nosebleeds. In more serious cases, vessel inflammation and fragility can cause internal bleeding or organ injury and may require urgent evaluation.
Sarcoma-Related Symptoms: Sarcomas often remain silent until they grow large enough to compress nearby tissues. Some bone sarcomas cause persistent bone or joint pain, swelling, or a feeling of fullness in a limb. Others present as a lump under the skin that may or may not be tender to the touch. As sarcomas enlarge or spread, they can cause new pain, weight loss, fatigue, breathing problems, or other symptoms, depending on where they grow and which organs they affect.
Autoimmune Malfunction: Autoimmune connective tissue diseases develop when the immune system mistakenly targets the body’s own connective tissues. Immune cells and antibodies drive ongoing inflammation, which damages joints, muscles, skin, blood vessels, and internal organs over time. The exact triggers are not fully understood, but genetic susceptibility, infections, and environmental exposures may all contribute.
Genetic Changes in Structural Proteins: Genetic connective tissue diseases arise from inherited or de novo gene changes that alter the production or assembly of key structural proteins, such as collagen or elastin. These changes can make tissues too weak, too stretchy, or structurally abnormal. The resulting problems may appear in infancy, childhood, or adulthood and can affect bones, joints, eyes, skin, heart valves, and blood vessels.
Malignant Cellular Growth: Sarcomas occur when cells in bone, cartilage, fat, muscle, or other connective tissues begin to grow and divide uncontrollably. Instead of maturing and functioning normally, these cells accumulate as a tumor that can invade nearby structures and spread to distant organs. The precise reasons why a normal connective tissue cell transforms into a sarcoma cell are not fully understood, but genetic mutations, prior radiation exposure, or certain inherited conditions may increase the risk.
Environmental and Other Risk Factors: For many connective tissue diseases, scientists have not identified a single cause. Severe or repeated infections that strain the immune system, exposure to certain toxic chemicals or medications, and chronic mechanical stress may increase vulnerability in people who are already genetically predisposed. In some cases, no clear triggering factor is ever found.

Diagnosis and Testing

How are connective tissue diseases and sarcomas diagnosed?

Clinical Evaluation and History: Diagnosis begins with a detailed medical and family history and a physical examination. Healthcare professionals ask about symptoms such as pain, stiffness, fatigue, rashes, breathing difficulties, and changes in blood pressure or heartbeat. They also look for visible or palpable lumps, skin changes, joint swelling, or signs of organ involvement and ask about similar conditions in relatives.
Imaging Studies: Imaging studies help visualize bones, joints, soft tissues, and internal organs. X-rays can show bone damage, deformities, or certain tumors. Magnetic resonance imaging scans and computed tomography scans provide detailed views of soft tissues, cartilage, muscles, and deeper structures and are often used to characterize suspected sarcomas or complex connective tissue involvement.
Laboratory Markers of Inflammation: Blood tests that measure inflammation markers, such as C-reactive protein and erythrocyte sedimentation rate, help identify ongoing inflammatory activity. Elevated levels can support a diagnosis of autoimmune connective tissue disease or signal a flare, but they are not specific and must be interpreted alongside clinical findings and other tests.
Autoantibody Testing: Autoimmune connective tissue diseases often produce specific autoantibodies that can be detected in the blood. Testing may include panels for antineutrophil cytoplasmic antibodies and other targeted antibodies associated with conditions such as lupus, Sjögren’s syndrome, scleroderma, myositis, or mixed connective tissue disease. The presence, pattern, and level of these antibodies help refine the diagnosis.
Tests for Gland and Organ Function: For conditions that affect moisture-producing glands, tests for dry eyes or dry mouth may include measurements of tear production and assessments of salivary flow. Other organ function tests, such as lung function tests, echocardiography, kidney function tests, or gastrointestinal evaluations, help assess the extent to which a connective tissue disease has progressed and which organs are involved.
Blood and Urine Testing: Routine and specialized blood and urine tests provide information about anemia, platelet counts, kidney and liver function, muscle enzymes, and markers of tissue damage. Changes in these results can signal organ involvement, inflammation, or treatment side effects and guide decisions about therapy and monitoring.
Tissue Biopsy: A tissue biopsy involves taking a small sample of skin, muscle, gland, bone, or tumor for examination under a microscope. In autoimmune or genetic connective tissue diseases, biopsy can reveal characteristic patterns of inflammation or structural abnormalities. In sarcomas, biopsy is essential to confirm the diagnosis, determine the tumor type and grade, and plan appropriate treatment.

Management and Treatment

How are connective tissue diseases and sarcomas treated?

Symptom Control and Organ Protection: Most connective tissue disorders are long-term conditions that require ongoing care. Treatment focuses on controlling pain, stiffness, and fatigue, while also protecting organs from damage. Management plans often combine medications, physical therapy, occupational therapy, and lifestyle strategies designed to preserve function and maintain quality of life.
Anti-Inflammatory and Immunosuppressive Medications: Autoimmune connective tissue diseases are often treated with medications that calm inflammation and regulate the immune system. These may include nonsteroidal anti-inflammatory drugs, corticosteroids, disease-modifying antirheumatic drugs, biologic therapies, or small-molecule targeted agents. The goal is to reduce disease activity, prevent flares, and limit long-term tissue damage while balancing potential side effects.
Treatment of Sarcomas: Sarcoma treatment generally centers on surgery to remove the tumor, often combined with radiation therapy or chemotherapy. The exact approach depends on the type, size, location, and stage of the sarcoma, as well as the person’s overall health and other conditions. In some cases, targeted therapies or immunotherapies may also be used. Care is usually coordinated by a multidisciplinary team experienced in soft tissue and bone cancers.
Supportive Therapies and Rehabilitation: Supportive therapies play a crucial role in managing connective tissue diseases. Regular, low-impact exercise or structured physical therapy can help maintain joint mobility, muscle strength, and cardiovascular fitness. Occupational therapy may offer strategies and adaptive tools for daily activities. Pain management, nutritional guidance, and mental health support are often important components of comprehensive care.
Emerging and Future Treatments: Scientists are investigating new treatments, including genetic and molecular therapies, to correct or mitigate the effects of underlying genetic changes in hereditary connective tissue disorders. Research is also ongoing into more targeted immune therapies for autoimmune diseases and more precise drugs for sarcomas. While these approaches are still developing, they offer hope for more specific and less toxic treatments in the future.

Living With

How can I take care of myself while living with a connective tissue disease or sarcoma?

Living with a connective tissue disease or sarcoma often means adapting to changes that can affect multiple parts of life. Regular follow-up with healthcare providers allows for early detection of flares, complications, or treatment side effects. Providers can also advise on vaccinations, screening tests, and preventive care that reduce the risk of infection and protect bone, heart, and lung health.

Self-care strategies may include pacing activities to manage fatigue, choosing low-impact exercises that are safe for joints and the cardiovascular system, and using stress-reduction techniques to support mental well-being. Nutrition, sleep, and avoiding tobacco and other harmful substances are also important. Because each condition and person is unique, the most effective plan is individualized and developed in close partnership with a care team that understands the specific connective tissue disease, its treatments, and its long-term outlook.

The IWBCA provides the information and materials on this site for educational and informational purposes only. The content is not a substitute for professional medical evaluation, diagnosis, or treatment. Always consult your physician or another qualified healthcare provider with any questions about a medical condition, diagnosis, or course of treatment. Do not disregard, delay, or alter medical advice based on information obtained from this site. If you believe you are experiencing a medical emergency, call 911 or your local emergency services immediately.