Difference Wiki

Pt vs. Ptt

PTT and PT abbreviated as ‘partial thromboplastin time’ and the ‘prothrombin time’ respectively are the two types of tests that are conducted to check out the time taken for the blood to clot. Both  tests are essential to diagnose the blood quality and can also alarm about the excessive blood loss in case of injury if not sufficient blood clots form. The PTT test is the measurement of the intrinsic coagulation pathway along with the common coagulation pathway. On the other hand, PT is also known as INR (International Normalized Ratio), which measures the prothrombin ratio; it also checks that whether the medicines to avoid the clotting is working or not. Most of the time, both these tests to examine the bleeding problems are conducted at the same time.

Key Differences

The normal PT result is from 11 to 16 seconds, whereas the normal PTT result is from 25 to 39 seconds.
Harlon Moss
Jul 15, 2017
In PT, the measurement of prothrombin ratio is done along with the INR (International Normalized Ratio). On the other hand, in PTT, the measurement of the intrinsic coagulation pathway along with the coagulation pathway is done.
PT is abbreviated as ‘Prothrombin Time,’ whereas PTT is abbreviated as ‘Partial Thromboplastin Time.’
In PTT, the heparin level in the body is closely measured, while in PT, warfarin level and vitamin K level are evaluated for the better tests.

Comparison Chart


Prothrombin time.
Partial thromboplastin time.

Medicines Evaluation

Warfarin level and vitamin K level.
Heparin level.

Normal Results

11 to 16 seconds.
25 to 39 seconds


I, II, V, VII, and X.
I, II, V, VIII, IX, X, XI, and XII.
Harlon Moss
Jul 15, 2017

Pt and Ptt Definitions


Initialism of physical training, a physical education class in grade school.


(countable) point


(countable) part


Abbreviation of patient


A heavy precious metallic element; gray-white and resistant to corroding; occurs in some nickel and copper ores and is also found native in some deposits

What is Pt?

PT (Prothrombin Time) is the test that is conducted to assess the time taken for the blood to clot; it is an essential test to examine the bleeding problems. If the blood already quite clots to the extent that it can cause the severe health issues, in PT, it is observed that whether the medications taken to prevent the blood clotting are working rightly or not. It will be relevant to mention here that, blood clotting is life-saving and healthy as it refrains from excessive blood loss during injuries or any surgery, but at the same time the abnormal clotting of the blood can bring the severe issues like heart attack and stroke. The prothrombin Test is also called the International Normalized Ratio (INR) as in this the standard prothrombin time test is conducted regardless of the testing methods. The INR test lets your doctor examine the prothrombin test even it has come from the different lab with using the different technique. Due to the standard verification of the INR test, some of the labs only give the INR tests. In this test, the clotting factors like I, II, V, VII, and X are examined. In the PT test, the warfarin and vitamin K level in the blood is also evaluated, to come up with the more compact results. As we know that this test tells about the time taken for the blood to clot; normally it takes 11 to 16 seconds if you are not using any medicines. If your blood doesn’t clot as per the normal time, then you might be suffering from the vitamin K deficiency or even be using the wrong dose of the warfarin.

What is Ptt?

Partial Thromboplastin Time (PTT) is another blood test that measures the time taken by the blood to clot. In other words, we can say that it assess the ability of the body to form blood clots to avoid the excessive loss in case of any injury or during the surgery. In PTT, the level of the heparin in the body is also examined as medications such like this can cause the thinning of the blood. This test investigates the factors working out for the excessive bleeding or the clotting; although it works at the initial level and if any abnormalities found several more tests can be referred for better knowing about the condition of the blood. The PTT evaluates the hemostasis, which is the process of blood clot formation and preventing the excessive blood loss due to an injury. The clotting factors that are examined in PTT are I, II, V, VIII, IX, X, XI, and XII. And the normal value taken from these tests is in between the 25 to 35 seconds. The intake of the medicines like warfarin, heparin, and aspirin before the test can affect the test, so it is it is often advised to skip these medicines before giving the samples for test.

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