If the patient is close to a family member or friend who has undergone surgical treatment for various reasons and has been exposed to anesthesia as a result, the patient may have heard conversations like these. Are these words true? Is anesthesia just a shot, a push of some medicine, and it doesn’t hurt at all? Is it true that some people are insensitive to anesthesia and need more of it than others? Is it true that some people don’t even work with anesthesia and still have to endure pain to undergo surgery? Does anesthesia really not hurt at all? It takes a lot of time and expertise to clarify these questions. And here, only a cursory introduction can be given to you. Painlessness is one of the basic requirements of anesthesia, which is called “analgesia”. The meaning of analgesia is not only to make the patient comfortable, but also to reduce the adverse stress response of the body in the face of pain and other injurious stimuli. When the body encounters some unexpected events (such as panic and pain), it will spontaneously initiate a series of defense processes, which is called stress response in medical science. For example, the release of various hormones in the organism increases. These stress reactions, some of which are protective and some of which can be damaging. For example, the body increases blood pressure and heart rate due to increased secretion of adrenaline during pain, and in the case of patients with heart disease, these changes may lead to the development of acute myocardial infarction. Only when the analgesia is adequate and the patient does not feel pain, can he or she undergo the surgery in a stable state. Here, the smoothness includes both the patient’s psychological smoothness when he is “awake” and the patient’s basic vital signs when he is “asleep” under general anesthesia. In other words, the analgesia pursued by anesthesiologists is not only to solve the pain that “awake” patients can actively express, even if the patient is “asleep” and cannot express it through words, the anesthesiologists will still choose the necessary methods and drugs to suppress the objective existence of Even if the patient is “asleep” and cannot verbalize the pain, the anesthesiologist will still choose the necessary methods and drugs to suppress the objective pain. As mentioned above, there are two types of patients: “awake” and “asleep”. Yes, they do. Depending on the needs of the surgery and the patient’s condition, the anesthesiologist will choose between general anesthesia, local anesthesia (nerve block, epidural, lumbar anesthesia), and other anesthesia methods. With local anesthesia, the patient can stay awake during the surgery but feel no pain at the surgical site. The specific differences and characteristics of these anesthetics have been described in the previous chapters, so I will not repeat them here. To put it simply, local anesthesia is to prevent nerves from transmitting various types of information to the brain at different sites, while general anesthesia is to prevent the brain from perceiving various types of information from peripheral nerves and to “block” the brain. So anesthesia does not hurt at all? There are exceptions to this rule. When local anesthesia is administered, the patient is unable to distinguish between “pain” and “perception” due to nervousness, and will feel “pain” during the operation. For example, in China, intra-vertebral anesthesia (a type of local anesthesia) is usually administered to women who have undergone a cesarean section. In this case, if the woman is particularly nervous and confuses the difference between “pain” and “perception”, she will cry “pain” regardless of whether the anesthesiologist touches the anesthetized area with a needle tip or a cotton swab. The anesthesiologist is confused between “pain” and “perception. At this point, what should the anesthesiologist do, will he change to general anesthesia? And given general anesthesia drugs, it will be absorbed by the baby through the placenta and cause the baby’s heartbeat, respiratory depression, and what to do? In general, the anesthesiologist will judge whether the anesthesia is effective or not based on past experience, such as whether the mother’s lower limbs feel heavy and whether the sweat hairs in the anesthetized area stand up. If the anesthesia effect is really bad, the anesthesiologist will change the anesthesia method to general anesthesia. Of course, in this case, it is necessary to be prepared for neonatal emergencies, and it is best to have a strong neonatal unit to back up. If the mother’s lower limbs are heavy and the sweat hairs in the anesthetized area are falling down (which indicates that the anesthesia is effective), for the safety of the fetus, the anesthesiologist will reassure the mother while prompting the obstetrician to start the procedure, and the mother will still feel “pain” and discomfort. After the fetus is removed, the anesthesiologist will consider whether to change to general anesthesia. In another case, when the intravertebral anesthesia is used, the patient will feel pain, nausea, vomiting, and sometimes indescribable discomfort when the operation pulls or pulls on the internal organs (e.g., appendix, gallbladder, uterus, etc.). There is no way to completely block this sensation. It is not said that “local anesthesia is to block the transmission of various types of information from nerves to the brain at different sites”, but since the nerve signal transmission in the surgical area has been blocked, why do we still feel the pull? This is related to the travel of the visceral nerves in the thoracic, abdominal and pelvic cavities of the body. Therefore, during intraspinal anesthesia, the nerve signal transmission is only blocked in the corresponding spinal cord segment, but the signal transmission of the vagus nerve, which does not pass through the spinal cord, is not prevented, which results in visceral pulling pain and nausea, vomiting and discomfort. In fact, due to individual differences, each patient feels differently about this kind of pulling pain and pulling reaction, and some can tolerate it without even a trace of discomfort, while others may change the anesthesia method because they cannot tolerate it at all. Therefore, during local anesthesia, the patient may feel “pain” due to both tension or pulling. This will lead to such words as “doctor, I resisted anesthesia during the last surgery, give me more anesthesia” and “anesthesia did not work at all, I know the whole procedure, I can feel the pain”. Since pelvic and abdominal surgery, intralesional anesthesia cannot completely block the transmission of nerve signals, so does general anesthesia mean that there is no pain at all? The answer is still no. In the process of general anesthesia, there is a possibility that the brain may not be fully “shielded”. Under what circumstances will there be “shielding” incomplete? This is mainly caused by insufficient application of anesthetic drugs and insufficient depth of anesthesia. At this point, the patient may feel nervous and think, “I will still feel pain after anesthesia! In fact, the patient can completely ignore this concern. We can tell you for sure that the development of modern medicine has enabled anesthesiologists to have enough methods, techniques and confidence to ensure that patients can perform all kinds of surgeries, large and small, under relatively comfortable and pain-free conditions. If local anesthesia does not work well, general anesthesia is an option. Having said all this, it is all about the pain or lack of pain after the anesthesia is administered. Will I feel pain during the anesthesia? This is true, because anesthesia drugs need to be delivered to the nerves or blood vessels through needles or tubes: for example, continuous epidural anesthesia requires a thick hollow steel needle to enter the spinal space through the ligament, and then a soft plastic tube is placed through the steel needle; for example, for some major surgeries, thicker intravenous needles are used to puncture or even central venous puncture is used to place the tube; in this process, pain is always inevitable. in this process, pain is always inevitable. However, the patient does not have to be too nervous about this kind of pain, which is close to the usual blood draw or intravenous needle, because during these operations, the anesthesiologist will administer some local anesthetic at the entry point to reduce the pain. And I believe that with the development of medical technology, the application of local anesthetic skin patches and other technologies will also make this pain less and less until one day, the whole process will be painless. Having said that, I believe that you will have a preliminary understanding of the relationship between anesthesia and pain. In fact, I hope that you will understand that anesthesia can make all patients undergo surgery under safe and pain-free conditions.