What effect does a hematoma have on subsequent blood draws?

A hematoma is a localized collection of blood outside of blood vessels, often caused by trauma to the tissue during a blood draw. When a hematoma occurs, it can complicate access to the vein for subsequent blood draws. This complication arises because the accumulation of blood can distort the anatomy of the area, making it difficult to identify and puncture the vein successfully. Additionally, the presence of a hematoma can cause tenderness and discomfort for the patient, which may amplify their anxiety about further needle sticks. As a result, phlebotomists must exercise greater caution, and the procedure may require additional time or alternative approaches to successfully collect blood.