Hyaluronic acid itself is a component of the skin that locks in moisture, provides a moisturizing effect, and improves the active state of the skin. At present, hyaluronic acid is mainly used for the filling of depressed tissue missing parts and the change of facial contour, such as nose job and chin augmentation. However, there are certain risks in the process of hyaluronic acid injection, as follows: 1. The most common risk is that hyaluronic acid is mistakenly injected into the blood vessels and necrosis of the skin tissue around the injection occurs. If the injection site is around the eye, it may also cause embolism of the eye artery, resulting in serious complications such as blindness, which is relatively rare; 2. Hyaluronic acid is a filler, which may shift after injection, failing to play a filling role and appearing different degrees of protrusion on the face, making the facial curve unattractive; 3. After injecting hyaluronic acid, the organism will have rejection allergic reaction, but the incidence is very low. Some people will have local redness, swelling and tissue hyperplasia 2-6 months after the injection, which is actually an allergic reaction of the tissue.