Tham khảo tài liệu 'chapter 112. venous thrombosis (part 1)', y tế - sức khoẻ, y học thường thức phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Chapter 112. Venous Thrombosis Part 1 Harrison s Internal Medicine Chapter 111. Venous Thrombosis Venous Thrombosis Introduction Venous thrombosis is the result of occlusive clot formation in the veins. It occurs mainly in the deep veins of the leg deep vein thrombosis DVT from which parts of the clot frequently embolize to the lungs pulmonary embolism PE . Fewer than 5 of all venous thromboses occur at other sites see Thrombosis at Rare Sites and Superficial Thrombophlebitis below . Venous thrombosis is common and often occurs spontaneously but it also frequently accompanies medical and surgical conditions both in the community and the hospital. The symptoms of venous thrombosis are nonspecific and therefore the clinical diagnosis is difficult and requires objective testing by imaging. Major complications of thrombosis include a disabling post-thrombotic syndrome and death due to fatal PE. Treatment with anticoagulants should be prompt and adequate. Many risk factors for thrombosis are known all of them related either to immobilization or to hypercoagulability. While it has no utility to assess the risk factor status after thrombosis has occurred several acquired risk factors are so strong that they warrant prophylactic anticoagulation in both those with and without a history of thrombosis. Detailed guidelines for primary prevention are available. Venous thrombosis tends to recur. The risk factors for a first venous thrombosis are not the same as for recurrent venous thrombosis and to a large extent are unknown. Individuals from families with inherited thrombophilia tend to develop thrombosis at a young age and to have frequent recurrences. Epidemiology The incidence of a first venous thrombosis is 1-3 per 1000 persons per year. Around two-thirds manifest as DVT of the leg and one-third as PE. Up to half of patients with PE have no signs of DVT. From 1-10 of venous thromboses prove fatal with deaths predominantly but not exclusively among the elderly or in .
