If a patient’s PT/INR and PTT results are elevated and they are not on anticoagulants, what is the most likely cause?

When both PT/INR and PTT results are elevated in a patient who is not on anticoagulants, it indicates a problem with the coagulation cascade that affects multiple pathways. The liver plays a central role in the synthesis of most clotting factors.

If the liver is not producing clotting factors adequately, it can lead to the elevation of both PT/INR (which is primarily associated with factors produced in the extrinsic pathway, such as factor VII) and PTT (which involves factors in the intrinsic pathway, like factors VIII, IX, XI, and XII). Conditions that compromise liver function—such as liver disease, cirrhosis, or severe hepatic injury—can significantly impair the liver's ability to synthesize these essential proteins, resulting in a coagulopathy.

In contrast, vitamin K deficiency primarily affects factors II, VII, IX, and X, leading to an increased PT/INR but typically does not cause an elevated PTT unless there is a severe deficiency that affects the intrinsic factors as well. Dehydration and uncontrolled hypertension do not directly cause a broad deficiency in clotting factor production, making them less likely explanations in this context. Therefore, the presence of elevated PT/INR and PTT