The substances used to do the test vary somewhat and a person’s PT may vary slightly from laboratory to laboratory. The PT and INR is in essence the same test. Liver disease, decreased vitamin K, decreased or defective factor VIIĭecreased or defective factor VIII, IX, XI or XII, von Willebrand disease, or lupus anticoagulant presentĭecreased or defective factor I, II, V or X, liver disease, disseminated intravascular coagulation (DIC)ĭecreased platelet function, thrombocytopenia, factor XIII deficiency, mild deficiencies in other factors, mild form of von Willebrand’s disease, weak collagen Comparison of the two results can give your healthcare team information as to the cause of a bleeding problem. The PT is often performed along with another clotting test called the aPTT (or sometimes the PTT or KCCT). Interpretation of PT and aPTT in Patients with a Bleeding or Clotting Syndrome Your healthcare team will use the INR to adjust your drug to get the PT into the range that is right for you. For some people who have a high risk of clot formation, the INR needs to be higher: about 3.0 to 4.0. a prothrombin time 2 to 3 times as long as in a person not on warfarin with normal clotting, using standardised conditions). People on anticoagulant drugs usually have a target INR of 2.0 to 3.0 (i.e. If you are not taking anticoagulant drugs and your PT is prolonged, additional testing may be necessary to determine the cause.įor monitoring of vitamin K-antagonists, such as warfarin, PT results are adjusted to the International Normalised Ratio (INR). An increased Prothrombin time or INR means that your blood is taking longer to form a clot. The test result for PT depends on the method used results will be measured in seconds. The effect of drugs such as warfarin can be determined by the prolongation of the PT (measured in seconds), or increase in the INR (a standardised ratio of the patient's PT versus a normal sample), and the dose adjusted accordingly. This is particularly important in people with heart conditions such as atrial fibrillation, with artificial heart valves and for people with blood clots.

Anticoagulant tablets help prevent the formation of blood clots (they do not 'thin the blood' as is commonly thought). One of the most common uses of the PT is to monitor the International Normalised Ratio (INR) of patients to check how well anticoagulant tablets such as warfarin and phenindione are working. The PT is one of the more sensitive tests to monitor serious liver disease (when the liver loses the ability to make essential proteins including clotting factors). The PT may also be measured before a surgical procedure (along with the APTT and fibrinogen) to check there are no defects in the clotting system that may lead to unexpected bleeding complications. The Prothrombin time (PT) test can be used to diagnose a bleeding disorder a healthcare professional will compare the PT with other clotting tests to indicate where in the clotting system a defect might lie (see table in ‘What does the test result mean?’ section). We are not a laboratory and are unable to comment on an individual's health and treatment. Lab Tests Online-UK is an educational website designed to provide patients and carers with information on laboratory tests used in medical care. If you are concerned about your test results, you will need to arrange an appointment with your doctor so that all relevant information including age, ethnicity, health history, signs and symptoms, laboratory and other procedures (radiology, endoscopy, etc.), can be considered. If the doctor wants to see you about the result(s), you will be offered an appointment. Your GP practice will be able to provide specific details. If you are registered to use the online services of your local practice, you may be able to access your results online. The X-ray & scan results may take longer. Some specialist test results may take longer, if samples have to be sent to a reference (specialist) laboratory. On average it takes 7 working days for the blood test results to come back from the hospital, depending on the exact tests requested. Urine Protein and Urine Protein to Creatinine Ratio.Urine Albumin to Creatinine Ratio or ACR.Unvalidated or misleading laboratory tests.Red Blood Cell (RBC) Antibody Identification.Heparin-induced Thrombocytopenia Antibody.Genetic Tests for Targeted Cancer Therapy.First Trimester (Combined) Screen for Down’s Syndrome and other fetal anomalies.

Factor V Leiden Mutation and PT 20210 Mutation.

Inr normal range on warfarin