Lupus, technically referred to as systemic LE (SLE), is an autoimmune disorder during which the body's system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary between people and should be mild to severe. Common symptoms include painful and swollen joints, fever, pain , hair loss, mouth ulcers, swollen lymph nodes, feeling tired, and a red rash which is most ordinarily on the face. Often there are periods of illness, called flares, and periods of remission during which there are few symptoms. The explanation for SLE isn't clear. it's thought to involve genetics along side environmental factors. Among identical twins, if one is affected there's a 24% chance the opposite one are going to be also . Female sex hormones, sunlight, smoking, vitamin D deficiency, and certain infections, also are believed to extend the danger . The mechanism involves an immune reaction by autoantibodies against an individual's own tissues. These are most ordinarily anti-nuclear antibodies and that they end in inflammation. Diagnosis are often difficult and is predicated on a mixture of symptoms and laboratory tests. There are variety of other forms of LE including discoid LE , neonatal lupus, and subacute cutaneous LE .