Autoimmune disease is a condition in which the body's immune system mistakenly attacks its own healthy cells, tissues, or organs instead of protecting against harmful invaders like viruses and bacteria

. Normally, the immune system can distinguish between foreign substances and the body's own cells, but in autoimmune diseases, this recognition fails, leading to immune system overactivity and damage to various parts of the body

. There are more than 80 to 100 different types of autoimmune diseases, which can affect nearly any organ or tissue, including joints, skin, muscles, blood vessels, endocrine glands (such as thyroid and pancreas), and internal organs

. Examples include rheumatoid arthritis, lupus, type 1 diabetes, multiple sclerosis, inflammatory bowel disease, and psoriasis

. The exact causes of autoimmune diseases are not fully understood, but they likely involve a combination of genetic predisposition and environmental triggers such as infections, chemicals, sun exposure, toxins, and lifestyle factors like smoking and obesity

. Women are more commonly affected than men, and having one autoimmune disease increases the risk of developing another

. Autoimmune diseases generally have no cure, but treatments focus on reducing immune system activity to manage symptoms and prevent tissue damage

. In summary, autoimmune diseases are disorders where the immune system attacks the body's own healthy cells, leading to inflammation and damage that can affect various organs and tissues