A Fibrinogen activity blood test from Walk-In Lab is typically ordered to help assess the cause of blood disorders (often problems with blood clotting) or thrombotic episodes. Additionally, patients order this blood test alongside other labs that test for cardiac risk or to aid in the monitoring of a progressive disease or the progress of an acquired condition.The Fibrinogen Activity Blood Test is also known as Factor I Activity and Clottable Fibrinogen. Patients are not required to fast when preparing for this lab and results are typically available within two to three days.Fibrinogen, a protein essential for blood clot formation, is produced by the liver and released as needed into the bloodstream. Typically, when a blood vessel wall or body tissue is injured, the coagulation cascade activates fibrinogen and more than 20 other clotting factors, one after the other. As the cascade nears completion, soluble fibrinogen changes into insoluble fibrin threads. The threads crosslink to form a fibrin net that stabilizes at the siteofinjury.The fibrin net adheres to the site of injury, along with platelets, and forms a stable blood clot. This blood clot serves as a barrier and prevents additional blood loss. The clot remains in place until the injured area heals completely. Fibrinogen is one of many blood factors called acute phase reactants. Along with other acute phase reactants, blood levels of fibrinogen rise sharply with some conditions, causing acute tissue inflammation or damage. A fibrinogen test measures the amount of soluble Factor I (which is fibrinogen dissolved in the blood) before it has turned into insoluble fibrin and crosslinked into a fibrin net.