Phosphatidylserine plays a role in blood coagulation (also known as clotting). Activation of prothrombin is crucial in physiological and pathological coagulation. Excess circulating thrombin results from the excess activation of the coagulation cascade. Activation of the coagulation system may precipitate disseminated intravascular coagulation. Prolongation of prothrombin time in coagulation testing is associated with severe bleeding manifestation. Caesarian section is contraindicated in cases of disseminated intravascular coagulation. Caesarean section carries an increased risk in cases of disseminated intravascular coagulation. Symptoms are high fevers and purple skin patches (purpura due to disseminated intravascular coagulation). Sodium Citrate is the anticoagulant used in specimens collected for coagulation tests. Kidney failure, disseminated intravascular coagulation (DIC), and pericarditis have also been reported. Sulfatide has roles in both blood coagulation and anticoagulation. Deficiencies of coagulation factors are associated with clinical bleeding. Neutrophils facilitate the blood coagulation by NETosis. This process is called coagulation or flocculation. Calcium is essential for maintaining cardiac membrane potentials and in regulating coagulation.