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High activated partial thromboplastin time (aPTT) in a blood test

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High activated partial thromboplastin time (aPTT) in a blood test
Last update: 21/05/2021

What is high activated partial thromboplastin time (aPTT) in a blood test called?

  • High activated partial thromboplastin time (aPTT)

What is the normal activated partial thromboplastin time (aPTT) in a blood test?

If you need to know which are the activated partial thromboplastin time (aPTT) reference ranges or you require more information about activated partial thromboplastin time (aPTT) in a blood test, you can visit normal activated partial thromboplastin time (aPTT) in a blood test.

What does a high activated partial thromboplastin time (aPTT) mean?

An increased activated partial thromboplastin time (aPTT), when the patient is not on anticoagulant therapy (heparin, warfarin, etc.) signifies a bleeding disorder. It takes the blood more time to form a blood clot and therefore there is a prolonged bleeding time when there is a hemorrhage.

A prolonged activated partial thromboplastin time (aPTT) may be due to:

  • Congenital deficiencies of blood clotting (hemophilia, Von Willebrand disease, etc.).
  • DIC (disseminated intravascular coagulation).
  • Anticoagulant therapy to prevent thrombosis using medication like heparin.

When activated partial thromboplastin time (aPTT) test is performed in conjunction with Prothrombin Time (PT), a further clarification of coagulation defects is possible. Used together, aPTT and PT will detect approximately 95% of coagulation defects.

A higher than normal activated partial thromboplastin time (aPTT) means:

  • Mild activated partial thromboplastin time (aPTT) increase (38 - 60 seconds in adults):

    A mild activated partial thromboplastin time (aPTT) increase should be studied.

    If you are not under anticoagulant therapy (heparin) and prothrombin time test (PT) is in the normal range it may be due to a congenital blood disorder such as hemophilia or Von Willebrand disease. Your doctor will decide if additional tests are required.

  • Moderate activated partial thromboplastin time (aPTT) increase (60 - 80 seconds in adults):

    If prothrombin time test (PT) is also higher than normal, it suggests DIC (disseminated intravascular coagulation). If prothrombin time test (PT) is in the normal range, it suggests hemophilia or Von Willebrand disease.

    If you are under anticoagulant therapy (heparin) to avoid thrombosis, these times may be considered appropriate. Your doctor may require you to perform this test frequently to know if the medication dose is adequate.

  • Severe activated partial thromboplastin time (aPTT) increase (> 80 seconds in adults):

    A sever activated partial thromboplastin time (aPTT) increase may lead to spontaneous bleeding that can be a serious health problem. Therefore, you should visit your doctor to find the underlying cause. It may be due to DIC (disseminated intravascular coagulation) or any other severe blood clot disorder.

    If you are under anticoagulant therapy (heparin), the time suggests more-than-adequate anticoagulation medication. You should speak to your doctor to reduce the dose.

Which factors can raise the activated partial thromboplastin time (aPTT) in a blood test?

There are some health circumstances or drugs than can raise the activated partial thromboplastin time (aPTT) in a blood test:

  • Vitamin K deficiency
  • Drugs
    • Anticoagulants
      • Argatroban
      • Dabigatran
      • Desirudin
      • Heparin
      • Lepirudin
      • Rivaroxaban
      • Warfarin
    • Antipsychotics
      • Chlorpromazine
    • Streptokinase
    • Urokinase

Which diseases can raise the activated partial thromboplastin time (aPTT) in a blood test?

The most common diseases why the activated partial thromboplastin time (aPTT) can be higher than normal are:

  • Antiphospholipid antibody syndrome
  • Congenital hypofibrinogenemia
  • Malabsorption
  • Congenital dysfibrinogenemia
  • Vitamin K deficiency bleeding (VKDB) of the newborn

What can I do to lower the activated partial thromboplastin time (aPTT) in a blood test?

If the activated partial thromboplastin time (aPTT) is higher than normal, you may try to increase vitamin K intake if vitamin K deficiency is the cause. Some vegetables like cauliflower, sprouts, spinach or kale are rich in vitamin K.

Where can I find more information about activated partial thromboplastin time (aPTT) in a blood test?

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Which values are considered a high activated partial thromboplastin time (aPTT) in a blood test?

The following values are considered to be above the normal range:

IMPORTANT: These levels are expressed in seconds. They are an example of a healthy man/woman of about 40 years old with no known disease and not taking any medication. The ranges can be different depending on the laboratory or on your personal circumstances.

Activated partial thromboplastin time (aPTT)
Mild activated partial thromboplastin time (aPTT) increase
38.1 s38.2 s38.3 s38.4 s38.5 s38.6 s38.7 s38.8 s
38.9 s39 s39.1 s39.2 s39.3 s39.4 s39.5 s39.6 s
39.7 s39.8 s39.9 s40 s40.1 s40.2 s40.3 s40.4 s
40.5 s40.6 s40.7 s40.8 s40.9 s41 s41.1 s41.2 s
41.3 s41.4 s41.5 s41.6 s41.7 s41.8 s41.9 s42 s
42.1 s42.2 s42.3 s42.4 s42.5 s42.6 s42.7 s42.8 s
42.9 s43 s43.1 s43.2 s43.3 s43.4 s43.5 s43.6 s
43.7 s43.8 s43.9 s44 s44.1 s44.2 s44.3 s44.4 s
44.5 s44.6 s44.7 s44.8 s44.9 s45 s45.1 s45.2 s
45.3 s45.4 s45.5 s45.6 s45.7 s45.8 s45.9 s46 s
46.1 s46.2 s46.3 s46.4 s46.5 s46.6 s46.7 s46.8 s
46.9 s47 s47.1 s47.2 s47.3 s47.4 s47.5 s47.6 s
47.7 s47.8 s47.9 s48 s48.1 s48.2 s48.3 s48.4 s
48.5 s48.6 s48.7 s48.8 s48.9 s49 s49.1 s49.2 s
49.3 s49.4 s49.5 s49.6 s49.7 s49.8 s49.9 s50 s
50.1 s50.2 s50.3 s50.4 s50.5 s50.6 s50.7 s50.8 s
50.9 s51 s51.1 s51.2 s51.3 s51.4 s51.5 s51.6 s
51.7 s51.8 s51.9 s52 s52.1 s52.2 s52.3 s52.4 s
52.5 s52.6 s52.7 s52.8 s52.9 s53 s53.1 s53.2 s
53.3 s53.4 s53.5 s53.6 s53.7 s53.8 s53.9 s54 s
54.1 s54.2 s54.3 s54.4 s54.5 s54.6 s54.7 s54.8 s
54.9 s55 s55.1 s55.2 s55.3 s55.4 s55.5 s55.6 s
55.7 s55.8 s55.9 s56 s56.1 s56.2 s56.3 s56.4 s
56.5 s56.6 s56.7 s56.8 s56.9 s57 s57.1 s57.2 s
57.3 s57.4 s57.5 s57.6 s57.7 s57.8 s57.9 s58 s
58.1 s58.2 s58.3 s58.4 s58.5 s58.6 s58.7 s58.8 s
58.9 s59 s59.1 s59.2 s59.3 s59.4 s59.5 s59.6 s
59.7 s59.8 s59.9 s60 s    
Moderate activated partial thromboplastin time (aPTT) increase
60.1 s60.2 s60.3 s60.4 s60.5 s60.6 s60.7 s60.8 s
60.9 s61 s61.1 s61.2 s61.3 s61.4 s61.5 s61.6 s
61.7 s61.8 s61.9 s62 s62.1 s62.2 s62.3 s62.4 s
62.5 s62.6 s62.7 s62.8 s62.9 s63 s63.1 s63.2 s
63.3 s63.4 s63.5 s63.6 s63.7 s63.8 s63.9 s64 s
64.1 s64.2 s64.3 s64.4 s64.5 s64.6 s64.7 s64.8 s
64.9 s65 s65.1 s65.2 s65.3 s65.4 s65.5 s65.6 s
65.7 s65.8 s65.9 s66 s66.1 s66.2 s66.3 s66.4 s
66.5 s66.6 s66.7 s66.8 s66.9 s67 s67.1 s67.2 s
67.3 s67.4 s67.5 s67.6 s67.7 s67.8 s67.9 s68 s
68.1 s68.2 s68.3 s68.4 s68.5 s68.6 s68.7 s68.8 s
68.9 s69 s69.1 s69.2 s69.3 s69.4 s69.5 s69.6 s
69.7 s69.8 s69.9 s70 s70.1 s70.2 s70.3 s70.4 s
70.5 s70.6 s70.7 s70.8 s70.9 s71 s71.1 s71.2 s
71.3 s71.4 s71.5 s71.6 s71.7 s71.8 s71.9 s72 s
72.1 s72.2 s72.3 s72.4 s72.5 s72.6 s72.7 s72.8 s
72.9 s73 s73.1 s73.2 s73.3 s73.4 s73.5 s73.6 s
73.7 s73.8 s73.9 s74 s74.1 s74.2 s74.3 s74.4 s
74.5 s74.6 s74.7 s74.8 s74.9 s75 s75.1 s75.2 s
75.3 s75.4 s75.5 s75.6 s75.7 s75.8 s75.9 s76 s
76.1 s76.2 s76.3 s76.4 s76.5 s76.6 s76.7 s76.8 s
76.9 s77 s77.1 s77.2 s77.3 s77.4 s77.5 s77.6 s
77.7 s77.8 s77.9 s78 s78.1 s78.2 s78.3 s78.4 s
78.5 s78.6 s78.7 s78.8 s78.9 s79 s79.1 s79.2 s
79.3 s79.4 s79.5 s79.6 s79.7 s79.8 s79.9 s80 s
Severe activated partial thromboplastin time (aPTT) increase
80.1 s80.2 s80.3 s80.4 s80.5 s80.6 s80.7 s80.8 s
80.9 s81 s81.1 s81.2 s81.3 s81.4 s81.5 s81.6 s
81.7 s81.8 s81.9 s82 s82.1 s82.2 s82.3 s82.4 s
82.5 s82.6 s82.7 s82.8 s82.9 s83 s83.1 s83.2 s
83.3 s83.4 s83.5 s83.6 s83.7 s83.8 s83.9 s84 s
84.1 s84.2 s84.3 s84.4 s84.5 s84.6 s84.7 s84.8 s
84.9 s85 s85.1 s85.2 s85.3 s85.4 s85.5 s85.6 s
85.7 s85.8 s85.9 s86 s86.1 s86.2 s86.3 s86.4 s
86.5 s86.6 s86.7 s86.8 s86.9 s87 s87.1 s87.2 s
87.3 s87.4 s87.5 s87.6 s87.7 s87.8 s87.9 s88 s
88.1 s88.2 s88.3 s88.4 s88.5 s88.6 s88.7 s88.8 s
88.9 s89 s89.1 s89.2 s89.3 s89.4 s89.5 s89.6 s
89.7 s89.8 s89.9 s90 s90.1 s90.2 s90.3 s90.4 s
90.5 s90.6 s90.7 s90.8 s90.9 s91 s91.1 s91.2 s
91.3 s91.4 s91.5 s91.6 s91.7 s91.8 s91.9 s92 s
Medically reviewed by our Medical staff on 21/05/2021

Bibliography

  • Concise Book of Medical Laboratory Technology Methods and Interpretations. 2nd edition. 2015. Ramnik Sood. ISBN 978-93-5152-333-8. Pag 293.
  • The Gale Encyclopedia of Nursing & Allied Health. 2002. Kristine Krapp. ISBN 0-7876-4934-1. Pag 517.
  • A Manual of Laboratory and Diagnostic Test. 9th edition. Frances Fischbach. Marshall B. Dunning III. 2014. Pag 156. ISBN-10: 1451190891.
  • Laboratory tests and diagnostic procedures with nursing diagnoses (8th ed), Jane Vincent Corbett, Angela Denise Banks, ISBN: 978-0-13-237332-6, Pag. 310.
  • Essentials of Medical Laboratory Practice. Constance L. Lieseke, Elizabeth A. Zeibig. 2012. ISBN: 978-0-8036-1899-2 Pag: 323.

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