Doctors often make the diagnosis based on the patient’s description of the color changes that occur suddenly after being exposed to cold temperatures. Sometimes doctors immerse the patient’s hand in ice water to provoke an episode. However, this test doesn’t always work because usually the whole body needs to be exposed to cold before an attack occurs.
There is no single blood test that identifies Raynaud’s. However, doctors might order bloodwork to rule out the presence of auto-antibodies associated with scleroderma, lupus, mixed connective tissue disease, undifferentiated connective tissue disease, Sjogren’s syndrome, and other diseases that have Raynaud’s as a possible component.
Some specialists (usually rheumatologists) perform a nailfold capillaroscopy, a simple microscopic examination of the small blood vessels at the base of the fingernail. This test is used also to look for the presence of an underlying connective tissue disorder.
