Certified Pediatric Hematology Oncology Nurse (CPHON) 2025 – 400 Free Practice Questions to Pass the Exam

Patients with Sickle Cell Disease (SCD) experience pain crises primarily because high blood viscosity leads to vascular occlusions. In SCD, abnormal hemoglobin (HbS) causes red blood cells to assume a sickle shape, particularly under conditions of dehydration, low oxygen levels, or other stressors. These sickled cells are rigid and can obstruct blood flow in small vessels, resulting in vaso-occlusive crises.

The pain associated with these crises arises from the ischemia (lack of blood flow) and resultant tissue damage that occurs when blood flow is blocked. This disruption of circulation can lead to severe pain, particularly in areas like the chest, abdomen, and joints. Understanding the mechanism of pain crises in SCD highlights the critical role that blood viscosity and vessel obstruction play in the disease's pathophysiology. Other options may relate to factors that can exacerbate the situation, but the fundamental cause of pain crises is directly linked to vascular occlusions resulting from the unique characteristics of sickled red blood cells.