Autoimmune diseases can be difficult to diagnose during the early stages of disease. How difficult the specific diagnosis is will depend on the type of autoimmune disease and the symptoms experienced by the patient, which may come and go. In other instances, the disease may progress unnoticed for some time.

For example, people with type 1 diabetes may not recognize early warning signs, such as excessive thirst or unexplained weight loss. For some individuals, the condition may not be diagnosed until a severe complication, such as ketoacidosis, occurs and results in the need for immediate medical attention.

In most cases, a physician’s diagnosis will rely on the patient’s medical history, a physical examination and medical testing. In compiling the medical history, a physician may ask about the symptoms the patient is experiencing, whether there are any patterns of their occurrence, triggering incidents or other contributing factors.

Patients may wish to keep a symptoms list or diary of when symptoms occur and any groups of symptoms that are experienced together. Patients should share this list with their physician, as well inform the physician of any family members with similar symptoms or other autoimmune diseases.

No single diagnostic test can detect an autoimmune disease. Autoantibody blood tests may identify the misguided antibodies that attack healthy body cells. These tests may also be used to rule out other possible causes of a patient’s symptoms.

No definitive diagnosis criteria are available for many of the autoimmune diseases. Instead, numerous consultations with medical specialists and tests performed over months to years may be necessary to determine the presence of such a disorder.

For some autoimmune disorders, people with known risk factors such as family history may be advised by their physician to undergo genetic tests or regular screening tests, such as thyroid blood tests or glucose tests.