Prothrombin time (PT) is increased in which condition?

Prothrombin time (PT) is increased in which condition?

• A. Hyperthyroidism
• B. Kidney failure
• C. Liver disease
• D. Anemia

Answer: (C)

Prothrombin time is a measure of the extrinsic pathway of coagulation and mainly reflects liver synthetic function because the liver produces most of the clotting factors in this pathway, particularly factor VII which has the shortest half-life. When the liver is diseased, its ability to produce these factors drops, leading to a longer PT. The other conditions listed don’t specifically impair hepatic production of these clotting factors in the same way, so they don’t reliably cause an increased PT.

Prothrombin time is a measure of the extrinsic pathway of coagulation and mainly reflects liver synthetic function because the liver produces most of the clotting factors in this pathway, particularly factor VII which has the shortest half-life. When the liver is diseased, its ability to produce these factors drops, leading to a longer PT. The other conditions listed don’t specifically impair hepatic production of these clotting factors in the same way, so they don’t reliably cause an increased PT.