It is easy to understand that rheumatic diseases cause lesions of joints, muscles, fascia and bursa, but it is rarely thought that rheumatic diseases can cause multi-system damage, and it is even less easy to think that rheumatic diseases can lead to intravascular thrombosis or embolism. There are many lesions with intravascular thrombosis or embolism, and the symptoms do not improve significantly with conventional anticoagulation and thrombolytic therapy. Instead, the disease is rapidly controlled with the addition of immunosuppressive drugs and adrenocorticosteroids. It is important to think broadly when diagnosing the disease clinically, especially when the treatment is unsuccessful, especially to reflect on the correctness of the diagnosis. I. The main symptoms of intravascular thrombosis or embolism: The clinical manifestations vary according to the different sites of thrombosis or embolism. (1) Lesions occurring in the blood vessels of the extremities, manifesting as limb pain, numbness, coldness, gangrene, or skin ulcers that do not heal easily, or intermittent claudication, and in severe cases, limb necrosis. (2) Lesions occurring in the visceral vessels, manifesting as abdominal pain or chest pain, moderate or severe pain, and in severe cases may cause shock. (3) The lesion occurs in the blood vessels of the brain, manifested as headache, dizziness, or sudden fainting, may be accompanied by nausea and vomiting, hemiparesis, speech disorder, or facial palsy, or numbness and abnormal sensation of the limbs. What should I do if I have the above symptoms? If intravascular thrombosis or embolism is suspected, CT of head, color Doppler examination of limbs or internal organs, or intravascular angiography can be done, the latter of which has certain risks. (3) How to determine the above manifestations as a result of rheumatism, one or more of the following should be considered as rheumatism: (1) with multi-system damage such as lung, kidney and blood (2) with Raynaud’s phenomenon, i.e. the change of pale, then cyanotic, then flushed skin on the unterminated limb (3) with unexplained pleural and abdominal effusion (4) positive rheumatoid factor and antinuclear antibody (5) positive antiphospholipid antibody or lupus anticoagulant substance, or false positive syphilis serologic test (6) positive anti-ds-DNA and anti-Sm antibody (7) positive anti-neutrophil cytoplasmic antibody (8) unexplained nasal bridge collapse, i.e. saddle nose. or with erythema nodosum. (4) Common rheumatic diseases leading to intravascular thrombosis or embolism. There are very many rheumatic diseases that can cause intravascular thrombosis or embolism, mainly including: systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, systemic vasculitis (including aortitis, giant cell arteritis, polyarteritis nodosa, Wegener’s granulomatosis, Kawasaki disease), antiphospholipid antibody syndrome, recurrent nonsuppurative nodular lipofuscinosis.