Why should you avoid using a site with visible veins that are bruised or scarred?

Avoiding sites with visible bruises or scars is essential because such conditions indicate potential underlying issues with the blood vessels. Bruised or scarred veins can make venipuncture more challenging and may not provide a clean flow of blood. This can lead to complications such as hematoma formation, which occurs when blood leaks into the surrounding tissue, causing swelling and pain. Additionally, complications can arise during the draw, including difficulty accessing the vein, which can result in improperly collected samples that might be contaminated or compromised. This could affect laboratory results, leading to inaccurate diagnoses or treatment plans. Therefore, selecting a site without visible bruising or scarring is crucial for patient safety and ensuring the integrity of the blood sample collected.