Lymphology Association of North America (LANA) Practice Exam

A patient presents with edema of the lower extremities and recent bloodwork reveals a lower than normal plasma albumin level. What is the most likely cause of this patient's edema?

1. Hyperproteinemia

2. Decreased capillary filtration

3. Hypoproteinemia

4. Increased capillary diffusion

The correct answer is: Hypoproteinemia

In this scenario, the patient's edema in the lower extremities is most likely caused by hypoproteinemia, which refers to a lower than normal concentration of proteins, particularly albumin, in the plasma. Albumin plays a critical role in maintaining oncotic pressure within the blood vessels; it helps to hold water in the bloodstream. When the albumin level decreases, as indicated by the recent bloodwork, it leads to a reduction in oncotic pressure. This drop allows fluid to leak out of the blood vessels and accumulate in the interstitial tissues, resulting in edema. Understanding the role of albumin is vital in recognizing how hypoproteinemia can lead to edema. In conditions where serum albumin is low, such as malnutrition, liver disease, or nephrotic syndrome, fluid shifts occur that can cause swelling in various parts of the body, including the lower extremities. The other options involve mechanisms that do not directly explain the cause of edema stemming from a low plasma albumin level. For example, hyperproteinemia would typically lead to increased oncotic pressure, helping to retain fluid within the vascular system, while decreased capillary filtration is associated with reduced fluid movement out of the capillaries, and increased capillary diffusion would