This condition is often due to gradual oozing of blood from the vascular puncture holes after blood collection, resulting in a subcutaneous hematoma that manifests itself as a purple bruise on the skin. Cold compresses should be applied once this occurs to prevent the bleeding from continuing to worsen, and hot compresses should be applied 24 hours later to promote dissipation of the local inflammation. Medications such as Xilotoxin can also be used, and applied topically to both reduce pain and accelerate absorption. In order to avoid blood leakage from the vessel after another blood collection, continuous pressure should be applied for at least 10 minutes after the blood collection to allow the vessel to clot.