Infusion when the needle eye did not press well, may lead to puncture point bleeding, subcutaneous bruising, mostly does not cause retrograde infection along the blood, the poor immunity of the population has a smaller chance of infection. After infusion and needle removal, if you usually have the use of aspirin, heparin and other anticoagulant drugs, so that the coagulation time is prolonged, the puncture port pressure time appropriately needs to be extended, if the puncture port pressure time is not enough, it will lead to bleeding from the puncture port, the appearance of subcutaneous bruising purple or puncture site bulging phenomenon, and continue to use hemostatic patches or swabs to press on the puncture port for 5 to 10 minutes, the bleeding can be stopped. Due to the pressure within the blood vessel, the puncture site is small, and the blood quickly coagulates to block the wound, which generally does not cause bacterial retrograde infection. However, if the puncture site is not handled with care, and the wound is contaminated with water on the same day, it can cause localized infection at the puncture site, but generally there is no retrograde blood infection or systemic infection. However, people with weak immunity such as diabetes, immunodeficiency, and the elderly have a chance of infection, but it is also small.