tromboembolism

Tromboembolism refers to the obstruction of a blood vessel by a clot that has formed at one site and migrated to another. The most common form is venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE). Arterial thromboembolism, originating from thrombi in the arterial system, can cause stroke or limb and organ ischemia. Together, thromboembolism is a major cause of cardiovascular morbidity and mortality worldwide.

Pathophysiology and risk factors: Thrombus formation is influenced by Virchow's triad—hypercoagulability, endothelial injury, and venous stasis. Risk factors include recent surgery or hospitalization, cancer, immobilization, pregnancy, estrogen therapy, obesity, inherited thrombophilias, and advanced age. Acquired states such as infection or inflammation can also contribute.

Clinical features and diagnosis: DVT commonly presents with leg swelling, pain, and warmth, while PE may cause sudden shortness of breath, chest pain, tachycardia, or syncope. Diagnostic approaches include compression ultrasonography for DVT and CT pulmonary angiography or ventilation–perfusion imaging for PE. D-dimer testing helps in low-risk cases to rule out VTE when imaging is not immediately available or indicated.

Management and prevention: Anticoagulation is the mainstay of treatment, typically initiated with heparin and followed by oral anticoagulants (warfarin or direct oral anticoagulants). The duration of therapy depends on the episode and risk factors, commonly around 3 months for a first provoked event and longer for ongoing risk. In massive or life-threatening PE, thrombolysis or surgical embolectomy may be considered. Preventive measures in high-risk settings include pharmacologic prophylaxis and mechanical methods such as compression devices.