Activated protein C resistance is a condition where the blood clotting system does not function normally. This can increase the risk of developing blood clots. There are several synonyms for activated protein C resistance, including factor V Leiden, factor V R506Q, APC resistance, and F5 Leiden mutation. These terms all refer to genetic mutations that lead to abnormal clotting. Identifying and treating activated protein C resistance is crucial to prevent dangerous blood clots. Treatments may include blood thinners or lifestyle changes, such as regular exercise and a healthy diet. It is important for individuals with a family history of thrombosis or blood clotting disorders to be tested for activated protein C resistance.