What is assessed in platelet function testing?

Platelet function testing specifically evaluates the ability of platelets to adhere to blood vessel walls and aggregate with each other, which are critical processes in the formation of a blood clot. This is essential for hemostasis, the process that prevents and stops bleeding. Tests may include methods that assess how well platelets can bind to von Willebrand factor and each other when exposed to various stimuli.

The other options do not directly pertain to platelet function testing. For instance, assessing fibrinogen concentration evaluates a component of the coagulation cascade but does not measure how platelets themselves behave. The rate of clot dissolution pertains more to the fibrinolytic system, while overall blood viscosity evaluates the thickness and flow characteristics of blood, which is influenced by multiple factors beyond just platelet activity. Thus, focusing on the adhesion and aggregation abilities of platelets is central to understanding their function in hemostasis.