When the weather gets colder, some people, especially women, will have bloodless fingers, some turn purple and blue, and also feel numbness or tingling in their fingers, and then their fingers will turn red when they warm up. What is this? This is a condition we call Raynaud’s phenomenon. When stimulated by cold or emotional stress, spasms and contractions of the small finger (toe) arteries suddenly occur, making the finger pale and then turn blue, and after the trigger is removed, the blood vessels relax and the finger turns to a normal red color. The typical Raynaud’s phenomenon refers to include one or several fingers or toes after cold or emotional stress, the color turns white, purple, after warmth turns red, the attack may be accompanied by local numbness or tingling department. Raynaud’s phenomenon most often affects the fingers and toes, persistent or frequent episodes of Raynaud’s phenomenon can lead to ischemic ulcers or necrosis of the finger (toe) ends. Patients with Raynaud’s phenomenon are often associated with pulmonary hypertension. Raynaud’s phenomenon is divided into primary and secondary. Primary Raynaud’s phenomenon is no underlying disease, although after years of follow-up can not be diagnosed as a disease. However, most Raynaud’s phenomenon is secondary. It can be secondary to a disease, such as connective tissue disease, drugs or toxins, structural abnormalities of the arteries, occupation-related (hand-arm vibration syndrome in drivers), and blood disorders. In a few normal people, the fingers may also turn white after stress or cold stimulation, but because there are no structural changes in the blood vessels, no lasting ischemia occurs and they remain unchanged as cyanotic. Raynaud’s phenomenon is often a manifestation of rheumatic immune diseases, for example, scleroderma, mixed connective tissue disease, systemic lupus erythematosus, dry syndrome, rheumatoid arthritis, etc. often have Raynaud’s phenomenon. Raynaud’s phenomenon can be an early first symptom of rheumatic immune disease, which can appear months or years before other symptoms. Therefore, Raynaud’s phenomenon is an important manifestation of rheumatic immune disease. The appearance of Raynaud’s phenomenon should first go to the Department of Rheumatology and Immunology to find out the cause of the disease and reduce missed diagnosis and misdiagnosis, which is important for the early diagnosis of rheumatic immune disease.