Protein S Deficiency is a genetic condition that affects the body's ability to regulate blood clotting. Protein S is a vital protein that helps prevent excessive clotting by acting as a cofactor for Protein C, which inactivates clotting factors. When there is a deficiency of Protein S, individuals may be at an increased risk of developing abnormal blood clots, particularly in veins, a condition known as venous thromboembolism. This deficiency can be inherited or acquired due to other medical conditions. Symptoms may include swelling, pain, or redness in the affected area, but some individuals may not experience noticeable symptoms. Diagnosis typically involves blood tests to measure Protein S levels, and treatment may include anticoagulant medications to reduce the risk of clot formation.