Definition: The immune system protects the body against disease, while the auto-immune system attacks your own body healthy cells, because it considers them as foreign invaders. Depending on the type, an autoimmune disease can affect one or many different types of body tissue.

The following are some of the more common autoimmune diseases:

• Rheumatoid arthritis: inflammation of joints and surrounding tissues
• Systemic lupus erythematosus: affects skin, joints, kidneys, brain, and other organs
• Celiac sprue disease: a reaction to gluten (found in wheat, rye, and barley) that causes damage to the lining of the small intestine
• Pernicious anemia: decrease in red blood cells caused by inability to absorb vitamin B-12
• Vitiligo: white patches on the skin caused by loss of pigment
• Scleroderma: a connective tissue disease that causes changes in skin, blood vessels, muscles, and internal organs
• Psoriasis: a skin condition that causes redness and irritation as well as thick, flaky, silver-white patches
• Inflammatory bowel diseases: a group of inflammatory diseases of the colon and small intestine
• Hashimoto’s disease: inflammation of the thyroid gland
• Addison’s disease: adrenal hormone insufficiency
• Graves’ disease: overactive thyroid gland
• Reactive arthritis: inflammation of joints, urethra, and eyes; may cause sores on the skin and mucus membranes
• Sjögren’s syndrome: destroys the glands that produce tears and saliva causing dry eyes and mouth; may affect kidneys and lungs
• Type 1 diabetes: destruction of insulin producing cells in the pancreas

Some of the causes of autoimmune diseases are believed to be caused by: bacteria or viruses, drugs, chemical irritants, environmental irritants.

Also, you may be more susceptible to developing an autoimmune disease if you are genetically predisposed to it.