The eleven criteria used for diagnosing systemic lupus erythematosus are:

• malar (over the cheeks of the face) "butterfly" rash
• discoid skin rash: patchy redness that can cause scarring
• photosensitivity: skin rash in reaction to sunlight exposure
• mucus membrane ulcers: ulcers of the lining of the mouth, nose or throat
• arthritis: 2 or more swollen, tender joints of the extremities
• pleuritis/pericarditis: inflammation of the lining tissue around the heart or lungs, usually associated with chest pain with breathing
• kidney abnormalities: abnormal amounts of urine protein or clumps of cellular elements called casts
• brain irritation: manifested by seizures (convulsions) and/or psychosis
• blood count abnormalities: low counts of white or red blood cells, or platelets
• immunologic disorder: abnormal immune tests include anti-DNA or anti-Sm (Smith) antibodies, falsely positive blood test for syphilis, anticardiolipin antibodies, lupus anticoagulant, or positive LE prep test
• antinuclear antibody: positive ANA antibody testing

In addition to the eleven criteria, other tests can be helpful in evaluating patients with SLE to determine the severity of organ involvement. These include routine testing of the blood to detect inflammation (for example, a test called the sedimentation rate), blood chemistry testing, direct analysis of internal body fluids, and tissue biopsies. Abnormalities in body fluids and tissue samples (kidney, skin, and nerve biopsies) can further support the diagnosis of SLE. The appropriate test procedures are selected for the patient individually by the doctor.