Lupus can be difficult to diagnose as the symptoms come and go and mimic those of many other illnesses. Some symptoms of lupus can be transient such as joint and muscle pain, fatigue, a rash caused or made worse by sunlight, low-grade fevers, hair loss, pleurisy, appetite loss, sores in the nose or mouth, or painful sensitivity of the fingers in cold environments.

SLE may be hard to diagnose and is often mistaken for other diseases. For this reason, lupus has often been called the "great imitator." No single test can tell if a person has lupus. There are many ways to diagnose SLE:

1. Medical history. Give your health care provider (HCP) a complete, accurate medical history. This information, along with a physical exam and special tests, helps your HCP rule out other diseases that can be confused with lupus.

2. Symptoms. Having 4 (or more) of the 11 symptoms of lupus, as defined below by the American College of Rheumatology.
   • Fever, fatigue, and weight loss
   • Arthritis lasting for several weeks in multiple joints
   • Butterfly-shaped rash over the cheeks or other rashes
   • Skin rash appearing in areas exposed to the sun
   • Sores in the mouth or nose lasting for more than a month
   • Loss of hair, sometimes in spots or around the hairline
   • Seizures, strokes, and mental disorders (depression)
   • Blood clots
   • Miscarriages
   • Blood or protein in the urine or tests that suggest poor kidney function
   • Low blood counts (anemia, low white blood cells, or low platelets)
3. Lab tests. The Antinuclear antibody (ANA) test is a commonly used test. An antibody is a chemical the body makes to fight off infections. The test looks for the strength of your antibodies. Most people with lupus test positive for ANA. However, other health problems, like malaria (a disease from a mosquito bite), can also give you a positive test. That's why other tests may be needed.