Sealing needles are a treatment commonly used for pain management in chronic conditions of tendons and other tissues. It can treat painful discomfort quickly and effectively. The main drugs used in it are local anesthetics and steroid hormones. However, there are some hazards, mainly related to the method of injection and the side effects of the drugs. Sealing needles are used to inject drugs into the local tissues using a syringe. During this process, the drug may be able to be injected into the blood vessels due to the incorrect method of injection. In rare cases, vascular embolism may occur, leading to problems such as ischemic necrosis of the tissues. This is one of the most serious hazards of closed needles. The drug components in closed needles are mainly local anesthetics and steroid hormones. Each of these drugs has its own characteristics and can lead to a number of health hazards. Local anesthetics can cause allergic reactions when used in a very small number of people. Allergy to local anesthetics may lead to respiratory and circulatory failure in the body, and life-threatening situations may occur if resuscitation is not timely. In addition, closed needles are used as a measure to treat pain, and local anesthetics have a certain timeliness, usually within a few hours. However, after the local anesthetic is completely metabolized by the body, painful discomfort at the injection site can occur, aggravating the painful symptoms of the original disease. However, it usually recovers within a few days and reduces the pain and discomfort. Steroid hormones also have some side effects. These drugs have the effect of inhibiting the body’s excretion of water and various tissues, and can also affect the body’s metabolism of fat, sugar and other nutrients. When the injection depth is too deep, there may be too much localized fat being metabolized, causing localized skin depressions and resulting in an unattractive appearance. Some people with diabetes can have their blood glucose raised after closed-needle treatment due to the effect of steroid hormones, and their blood glucose cannot be easily controlled. Steroid hormones can also lower the body’s immunity, and excessive use can lead to localized skin soft tissue infections, causing skin breakouts and erosions. Sealing injections are a treatment method that can effectively treat chronic pain. It requires mastery of injection techniques, reasonable drug ratios and strict indications to effectively avoid the hazards of closed needles.