Coumadin is the brand name for warfarin, an oral anticoagulant (blood thinner) used to prevent or treat harmful blood clots in veins or arteries. It is prescribed to reduce the risk of serious conditions such as stroke, heart attack, deep vein thrombosis (DVT), pulmonary embolism, and certain heart rhythm disorders. For patients undergoing diagnostic testing, including PT/INR testing (International Normalized Ratio), it's crucial to measure how long it takes blood to clot effectively. A Partial Thromboplastin Time (PTT) test also evaluates the function of specific blood clotting proteins, known as clotting factors. The goal is to maintain the INR within a target range (often 2.0–3.0 for most conditions, although this can vary based on medical needs outlined by the American Heart Association). Dosing is adjusted based on INR results, sometimes weekly or monthly. In addition, for certain health screenings, such as D.O.T drug testing or gender reveal testing, mobile phlebotomy services may offer convenient solutions for patients.