American Medical Certification Association (AMCA) Phlebotomy Practice Exam 2025 - Free Phlebotomy Practice Questions and Study Guide

The term "venous reflux" refers specifically to the backflow of blood from the collection tube back into the vein. This phenomenon can occur during venipuncture when the pressure inside the vein decreases, allowing some of the blood that has been drawn into the tube to flow back into the bloodstream. This is particularly relevant for phlebotomists to recognize because it can complicate the blood draw process, potentially affecting test results or leading to discomfort for the patient. Understanding venous reflux is important for maintaining the integrity of blood samples and ensuring proper technique during blood collection.

The other options pertain to different vascular concerns: obstruction refers to a blockage that prevents blood flow, the formation of a clot describes thrombosis, and leakage involves blood escaping into surrounding tissue which is often described in the context of hematomas or bruising. Each of these terms denotes a distinct medical condition that does not accurately capture the definition of venous reflux.