One factor is the pain caused by the damage to the mucous membrane of the skin during blood sampling, but this pain is easily recovered on its own relatively quickly and will not be prolonged. The other is due to blood leakage, such as improper operation during blood collection or insufficient pressure during needle removal, resulting in extravasation of blood, which can cause swelling and pain. Clinically, to relieve the symptoms, you can use some drugs to reduce swelling, such as some local methods, such as the use of some potato chips for local wet compresses or some magnesium sulfate to wet compresses can achieve good results, generally speaking is not recommended to use drugs. But if the patient’s pain is particularly severe, affecting the patient’s rest, sleep and other circumstances can be taken with the application of drugs. For example, the clinical application of some non-steroidal anti-inflammatory drugs, Loxone, ibuprofen and so on can achieve good results, clinically speaking, generally speaking, the problem is not big.