High von Willebrand Factor (vWF) Antigen Test: Causes, Inflammation, Clot Risk, and Meaning
A high von Willebrand factor antigen test means the blood contains more von Willebrand factor protein than expected for that laboratory’s reference range. Von...
INR and Warfarin: Interpreting Anticoagulation Results Without Overdoing It
INR is the blood test most often used to monitor warfarin. It shows how long your blood takes to clot compared with a standardized...
International Normalized Ratio (INR) Normal Range: Reference Values and Meaning
The international normalized ratio, or INR, is a blood test result that shows how quickly blood clots through the prothrombin time pathway. It is...
Low Activated Partial Thromboplastin Time (aPTT) Test: Causes, Clotting Risk, and Meaning
A low activated partial thromboplastin time, or low aPTT, means a blood sample clotted faster than the laboratory’s expected range. The aPTT test measures...
Low Anti-Xa Test Result: Causes, Heparin Dose, Clot Risk, and Meaning
A low anti-Xa test result usually means there is less measured anti-clotting drug effect in the blood than the target for that person’s treatment...
Low Factor II (Prothrombin) Activity Test: Causes, Bleeding Risk, and Meaning
A low factor II activity test means the blood sample has reduced prothrombin activity, which can make clots form too slowly. Prothrombin, also called...
Low Factor IX Activity Test: Causes, Hemophilia B, Bleeding Risk, and Meaning
A low factor IX activity test means the blood has reduced working factor IX, a clotting protein needed to form a stable clot after...
Low Factor V Activity Test: Causes, Bleeding Risk, and Meaning
A low factor V activity test means the blood has reduced working factor V, a clotting protein needed to build a stable fibrin clot...
Low Factor VII Activity Test: Causes, Prolonged PT, Bleeding Risk, and Meaning
A low factor VII activity test means the blood sample has less working factor VII than expected. Factor VII is a clotting protein made...
Low Factor VIII Activity Test: Causes, Hemophilia A, Bleeding Risk, and Meaning
A low factor VIII activity test means the blood has less working factor VIII than expected. Factor VIII is a clotting protein that helps...
Low Factor X Activity Test: Causes, Bleeding Risk, and Meaning
A low factor X activity test means your blood has reduced working factor X, a clotting protein needed to form a stable clot after...
Low Factor XI Activity Test: Causes, Bleeding Risk, Hemophilia C, and Meaning
A low factor XI activity test means the blood has less working factor XI than expected. Factor XI is a clotting protein that helps...
Low Factor XII Activity Test: Causes, Prolonged aPTT, and Meaning
A low factor XII activity test means the blood sample has reduced activity of coagulation factor XII, also called Hageman factor. This result often...
Low Fibrinogen Blood Test Causes, Bleeding Risk, and Meaning
Fibrinogen is a clotting protein that helps blood form a strong, stable clot after injury. A low fibrinogen blood test means the blood has...
Low International Normalized Ratio (INR) Blood Test Causes, Clotting Risk, and Meaning
A low international normalized ratio, or low INR, most often means blood is clotting faster than expected for the person’s treatment goal. The result...
Low Partial Thromboplastin Time (PTT) Test: Causes, Clotting Risk, and Meaning
A low partial thromboplastin time (PTT) result means the blood sample formed a clot faster than the laboratory’s reference range. This is less common...
Low Prothrombin Time (PT) Test: Causes, Clotting Risk, and Meaning
A low prothrombin time means a blood sample clotted faster than the laboratory’s reference range. PT is measured in seconds and is often reported...
Low Thrombin Time Test: Causes, Clotting Results, and Meaning
A low thrombin time means a blood plasma sample formed a fibrin clot faster than expected after the lab added thrombin. Thrombin time, often...
Low von Willebrand Factor (vWF) Antigen Test: Causes, Bleeding Risk, and Meaning
A low von Willebrand factor antigen test means the blood sample contains less von Willebrand factor protein than expected. Von Willebrand factor, often shortened...
Lupus Anticoagulant and Anticardiolipin Antibodies: Interpreting Antiphospholipid Panel
An antiphospholipid panel looks for immune proteins that can make blood more likely to clot in arteries, veins, or the small vessels of the...