The blood clot, which develops inside a blood vessel is known as thrombosis. In this condition the blood flow through the circulatory system is obstructed. This can occur in either veins or arteries. Atrial fibrillation is the most common cause of arterial thrombosis whereas venous thrombosis is majorly caused by a combination of hypercoagulability and venous stasis. In some cases a thrombus may get detached as an embolus and travel through circulation. This results in a type of embolism called thromboembolism. Low molecular weight heparin, insertion of a vena cava filter and mechanical calf compression are some of the methods used for its treatment. This book aims to shed light on some of the unexplored aspects related to thrombosis. It includes some of the vital pieces of work being conducted across the world, on various topics related to this medical condition. A number of latest researches have been included to keep the readers up-to-date with the global concepts in this area of study.