How is lupus diagnosed?
In lupus, something goes wrong with your immune system, the part of the body that fights off viruses, bacteria, and germs (“foreign invaders” like the flu). Normally, our immune system produces proteins called antibodies that protect the body from foreign invaders. When you have lupus, your immune system cannot tell the difference between these foreign invaders and your body’s healthy tissues, so autoantibodies (auto means self and anti means against: against self) are made that damage and destroy healthy tissue. These autoantibodies cause inflammation, pain, and damage in various parts of the body.
A doctor who is considering the possibility of lupus will look for signs of inflammation which include, pain, heat, redness, swelling, and loss of function at a particular place in the body. Inflammation can occur on the inside of your body (your kidneys or heart, for example), on the outside (your skin), or both.
There are many challenges to reaching a lupus diagnosis. Lupus is known as "the great imitator" because its symptoms mimic many other illnesses. Lupus symptoms can also be unclear, can come and go, and can change.
A physician will carefully review the following while evaluating a lupus diagnosis:
- your current symptoms
- your laboratory test results
- your medical history
- the medical history of your close family members (grandparents, parents, brothers and sisters, aunts, uncles, cousins)
All of this information may be necessary for a doctor to make a diagnosis of lupus.
A variety of laboratory tests are used to detect physical changes or conditions in your body that can occur with lupus. Each test result adds more information to the picture your doctor is forming of your illness. However, for a number of reasons listed below, laboratory tests alone cannot give a definite “yes” or “no” answer:
- No single laboratory test can determine whether a person has lupus.
- Test results that suggest lupus can be due to other illnesses or can even be seen in healthy people.
- A test result may be positive one time and negative another time.
- Different laboratories may produce different test results.
If multiple criteria are present simultaneously, a physician—a family practitioner, internist or pediatrician—may reach a lupus diagnosis. If, however, as is often the case, symptoms develop gradually over time, the diagnosis may not be as obvious, and consultation with a rheumatologist may be needed.
Medically reviewed on July 08, 2013