What tissues can be attacked by your immune system?

Your immune system can potentially attack virtually any tissue in the body during autoimmune conditions, though certain tissues are more commonly targeted. Autoimmune diseases demonstrate the immune system's capacity to mistakenly identify self-tissues as threats.

Commonly attacked tissues include joints (rheumatoid arthritis), pancreatic insulin-producing cells (type 1 diabetes), thyroid tissue (Graves' disease, Hashimoto's thyroiditis), nervous tissue myelin coating (multiple sclerosis), intestinal tissue (inflammatory bowel diseases), skin (psoriasis, vitiligo), salivary and tear glands (Sjögren's syndrome), and multiple tissue types simultaneously (systemic lupus erythematosus). The immune system can also attack blood vessels (vasculitis), liver tissue (autoimmune hepatitis), adrenal glands (Addison's disease), and neuromuscular junctions (myasthenia gravis). Some autoimmune reactions target specific tissue proteins—celiac disease involves immune attack against intestinal tissue triggered by gluten protein, while pemphigus involves antibodies against skin proteins holding epithelial cells together. The mechanisms driving these self-attacks involve complex breakdowns in immune tolerance—processes that normally prevent immune cells from attacking the body's own tissues. Risk factors include genetic predisposition (certain genes increase susceptibility), environmental triggers (infections, medications, toxin exposures), hormonal influences (explaining higher autoimmune disease rates in women), and molecular mimicry (where foreign proteins resemble self-proteins, causing confused immune responses). Autoimmune tissue attacks cause inflammation, progressive tissue damage, and impaired function. While most autoimmune diseases cannot be cured, immunosuppressive and anti-inflammatory treatments reduce tissue damage, preserve function, and improve quality of life. Early diagnosis and treatment significantly improve long-term outcomes, making medical evaluation of suggestive symptoms important.