PT and/or aPTT may be prolonged for a number of reasons.
Prolonged PT causes include:
- Warfarin therapy
- Liver disease
- Disseminated intravascular coagulation (DIC)
- Vitamin K deficiency
- Liver conditions such as cirrhosis or hepatitis
- Inadequate level of Factors I, II, V, VII, and/or X
Prolonged aPTT causes include:
- Presence of heparin
- Liver disease, other liver conditions
- Vitamin K deficiency
- Hemophilias
- DIC
- von Willebrand disease
- Lupus anticoagulant
- Inadequate levels of Factors I, II, V, VIII, IX, X, XI, and/or XII