Prothrombin time: what is it and why can it be high

The time of prothrombin or PT is a blood test that evaluates the capacity that has the blood to clot, es decir, the time necessary to stop a hemorrhage, for example.

Therefore, the prothrombin exam is used whenever bleeding or frequent bruising appears to try to detect which is the cause of the problem, as well as when looking for problems in the liver, and the measurement of liver enzymes is also requested. such as TGO, TGP and GGT, for example. Learn more about liver function problems.

In the case of people who use oral anticoagulants such as Warfarin or Aspirin, the doctor will periodically request the INR, which is a more specific measure than the PT to evaluate the effect of the drugs, since the PT is usually found high in these conditions.

Prothrombin, also known as coagulation factor II, is a protein produced by the liver, which when activated promotes the conversion of fibrinogen into fibrin, which together with platelets, forms a cap that prevents bleeding. Therefore, prothrombin is an essential factor for blood clotting to take place.

normal values

He normal value of it prothrombin time for a healthy person it must vary between 10 to 14 seconds. In the case of the INR, the value of a healthy person must vary between 0.8 and 1.

However, in case you are using oral anticoagulants, the value must be between 2 and 3, depending on the illness for which you need treatment with this type of medication.

Meaning of the results

The result of the prothrombin time test can change due to different causes, therefore, whenever there are changes, the doctor can ask for new tests to identify the correct cause and start treatment.

high prothrombin time

This result indicates that if a cut occurs, the bleeding will take longer to stop, since some more common causes are:

• Use of anticoagulants;
• Alteration of the intestinal flora;
• Poorly balanced diet;
• Liver diseases;
• Vitamin K deficiency;
• Coagulation problems such as hemophilia;

In addition, some medications such as antibiotics, corticosteroids and diuretics can also change the value of the exam, so it is advisable to inform the doctor about all the medication you are using.

Low prothrombin time

When the prothrombin value is lower than normal, it means that clotting occurs very quickly. Because bleeds are rarer and if they stop quickly, there is a greater risk of clots forming that can cause a heart attack or stroke.

Some of the causes that can cause this change are:

• Use of vitamin K supplements;
• Excessive consumption of foods with vitamin K such as spinach, broccoli or liver;
• Use of estrogen-containing pills such as contraceptive pills.

In these cases, it may be necessary to start the use of anticoagulants or heparin injections to identify the cause of the alteration. After this, the doctor will recommend the most appropriate treatment.