It is difficult to diagnose lupus because the symptoms vary widely from person to person, may change over time and overlap with other disorders. According to the American College of Rheumatology, if you have four of the following 11 criteria ― documented by a physician ― you probably have lupus. The four criteria can occur together or individually over time.
• Face rash — especially butterfly shaped on the nose and cheeks
• Scaly rash characterized by raised, scaly patches
• Sun-related rash
• Painless mouth sores
• Joint pain and swelling in two or more joints
• Inflammation of the membranes lining the heart or lungs
• Kidney disorder
• Seizures or psychosis
• Low blood counts, such as anemia
• Positive antinuclear antibody test
• Immunologic disorder — presence of certain antibodies
Source: American College of Rheumatology
