After taking your medical history and doing a physical exam, your health professional will assess your symptoms and run certain laboratory tests to confirm a diagnosis of Sjögren's syndrome. He or she will ask you for a list of the medications you take to determine whether they may be causing your symptoms or making your symptoms worse.

For consistent treatment of Sjögren's syndrome, criteria devised by a group of European health professionals are used to help diagnose cases of this disease and to identify cases in which a person has similar symptoms but has other medical problems that may be causing the symptoms. The following tests may help find inflammation of saliva gland tissue, decreased formation of tears or saliva, or certain substances in the blood:

• Schirmer's tests measure tear flow. In Schirmer I, a small strip of soft paper is placed in your lower eyelid to absorb your tear flow. Your health professional then measures the area of the paper moistened to evaluate the amount of tear flow. In Schirmer II, a cotton swab is placed gently into your nose to stimulate tear production, in order to measure how fast tears form in your eyes when you feel an irritation in your nose. One or both of these tests will help determine whether your tear (lacrimal) glands are responding properly.
• Rose Bengal tests measure potential damage to eyes. A small drop of dye is placed in your lower eyelid. The dye coats the surface of your eye and is then rinsed out. A slit lamp is then used to study the surface of the eye to look for dry or scratched areas. This test is usually performed by an ophthalmologist.
• Salivary function tests measure the amount of saliva you produce. A straw is placed in your mouth, which pools the saliva into a cup. Decreased saliva production is often present if you have Sjögren's syndrome.
• Blood tests for Sjögren's syndrome determine whether autoantibodies against anti-SS-A (Ro) and anti-SS-B (La) antigens are present in your blood. The presence of autoantibodies, which are proteins produced by the immune system, may help your health professional diagnose Sjögren's syndrome.
• Tissue biopsies are done to see whether the salivary gland tissue is inflamed. A small tissue sample (biopsy) is removed from a small salivary gland on the inside of your mouth.

Your health professional may do additional tests to check for evidence of other autoimmune diseases that also may cause dry eyes and mouth and other symptoms not related to Sjögren's. These tests include:

• Erythrocyte sedimentation rate, to find out whether a condition causing inflammation is present.
• Rheumatoid factor, to help support a diagnosis of rheumatoid arthritis.
• Antinuclear antibodies, to help diagnose systemic lupus erythematosus (SLE) and other suspected autoimmune diseases.