Hemostasis is a physiological process in the body that helps in stopping the bleeding and starting the repair process. This process prevents excessive blood loss and infections in the body. The formation of a blood clot inside a blood vessel, which obstructs the blood flow through the circulatory system is referred to as thrombosis. It can be categorized into venous thrombosis and arterial thrombosis. Venous thromboembolism (VTE) refers to blood clots that start in the veins. Deep vein thrombosis (DVT) and pulmonary embolism are the two sub-categories of VTE. Some common symptoms of thrombosis include sudden change in mental state, swelling in leg or arm, weakness in one side of the body, and chest pain. Diagnosis of thrombosis is performed through tests such as ventilation-perfusion scans, computed tomography (CT) scan, venography, and ultrasound. Anticoagulants such as heparin are the most effective medications used for the treatment of thrombosis. This book outlines the symptoms, diagnosis and treatment of thrombosis and hemostasis in detail. It consists of contributions made by international experts. The book is appropriate for students as well as for experts seeking detailed information in the area of hematology.