Understand lupus
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease. It can affect different parts of the body, and its pattern and severity vary from person to person and may change over time.
This information is educational. It does not diagnose your condition or replace advice from your healthcare team.
The immune system normally protects the body from infection and disease. In lupus, the immune system mistakenly attacks the body's own tissues, which can cause inflammation and sometimes tissue damage. Lupus may affect the skin, joints, kidneys, blood cells, heart, lungs or nervous system. Having lupus does not mean all of these organs will be affected.
There is no single known cause. Current evidence points to an interaction between genetic, immune, hormonal and environmental factors. Lupus is not contagious.
There is no single test that diagnoses lupus by itself. Clinicians combine your medical history, symptoms, examination, blood and urine tests, and sometimes additional tests or a biopsy. A positive antinuclear antibody (ANA) test alone does not confirm lupus.
Lupus can have periods when inflammation or symptoms increase and periods when disease is quieter. Fatigue alone or one abnormal test does not prove a flare. Your clinician considers symptoms, examination, tests, affected organs and your usual disease pattern.
Some problems can appear on tests before they cause obvious symptoms. Kidney involvement is an important example, so regular monitoring may be needed even when you feel well.
Last editorial update: October 2026.
Internal medical review: Pending documented clinician review. NA7N does not claim medical review before it occurs.