The tear trough is a concave groove on the lower eyelid near the side of the nose and is usually congenital. From the outside, people with tear troughs can look tired, which is usually the reason why many candidates seek medical attention. Hyaluronic acid injection for filling is one of the effective ways to solve the concave tear trough, but if the candidate chooses an unprofessional doctor to perform the injection operation, it may lead to the following adverse reactions: 1. Unevenness: because the eyelids are very thin, inexperienced or a little careless, it is easy to inject too much, resulting in localized unevenness; 2. Localized bruising: hyaluronic acid filling needs to rely on the syringe, and if you accidentally puncture the blood vessels around the eyes, it will also cause bruising; 3. 3, hard knot: the skin around the eyes is thin and loose, it is difficult to deal with, filling too shallow may appear local unevenness, you can also touch the small hard knots, therefore, the symptoms can be improved, do not use too much. To summarize, candidates should choose regular hospitals and experienced professional doctors, precise grasp of the injection site and drug dosage, to ensure the safety of injection, in order to achieve good micropigmentation results.