Cancer pain refers to the pain caused by malignant tumor, which is also known as cancer pain. Clinically, cancer pain is divided into three categories: [Category I] refers to pain caused by the tumor itself, which accounts for 75%-80% and is the main type of cancer pain; [Category II] refers to pain caused by treatment, such as chemotherapy, radiotherapy and some minimally invasive treatments, which accounts for 10%-15%; [Category III] refers to the chronic pain that usually accompanies cancer patients, such as trigeminal neuralgia, lumbar and leg pain or herpetic neuralgia. The third category] refers to the chronic pain usually associated with cancer patients, such as with trigeminal neuralgia, low back and leg pain or herpes zoster neuralgia. Some types of cancer can produce pain in early stages, and many patients come to the clinic because of pain before they are found to have malignant tumors. Therefore, early pain symptoms are also an indicator of tumor diagnosis. However, there are still most patients with early stage cancer who do not feel pain; when pain appears, it is often already in the middle to late stage. Especially for cancer patients who have already been treated, if pain occurs, they must seek for a specialist in time, as it may mean that the tumor has recurred or metastasized. Many cancer patients have acupuncture and massage when they have back and leg pain, but the pain becomes more and more serious, and only when they are finally examined, they find that they have bone metastasis. Due to the delayed condition, it is very difficult to treat again and the best treatment time is lost, and even paraplegia may occur. Does cancer pain pass after enduring it? Chinese people have a special cultural characteristic that they like to put up with everything first. Similarly, when cancer pain occurs, many patients also tend to put up with it first, often turning mild pain into severe pain and delaying easily treatable daily into intractable daily. In fact, cancer pain is a common phenomenon in the process of disease development. About 1/3 of early stage cancer patients will have pain, and about 90% of end-stage cancer patients will have pain. It can be said that about half of the patients will experience such pain from the time they are detected with cancer to the time they finally pass away. However, different attitudes and means of dealing with cancer pain will lead to different experiences of patients. Moreover, cancer patients who experience pain should not escape from it. Cancer pain is different from some chronic pains, for example, most joint pains have intermittent periods, which hurt for a while and get better after a while; however, cancer pain rarely has intermittent periods, and once the cancer progresses, the pain will become heavier and the degree of tissue damage will become more and more severe. For example, the pain produced by cancer bone metastasis will restrict the patient’s activities, and as the metastatic cancer increases the degree of destruction of nerves and tissues in the bones, fractures are more likely to occur, and in serious cases, the spinal cord will be compressed, leading to paraplegia. Therefore, cancer pain is not something that can be endured, but will become more and more serious if endured. Pain is a subjective feeling, so how should patients express their pain feeling when they visit the clinic? In clinical practice, since the location of pain is not easy to locate, and the nature and degree of pain are not easy to express, an important part of cancer pain treatment is to teach patients to describe their own pain characteristics. The first method is the pain numerical scoring method: draw a thick straight line, usually about 250px, on a white paper and mark the line in ten equal parts, from one end to the other with the numbers 0-10, with 0 representing no pain at all and 10 at the other end representing the most serious severe pain. The patient makes a mark at a point on the line to indicate the intensity of pain according to his or her pain level. The second method is the four-level pain assessment method: pain is divided into three levels: mild, moderate and severe, and painless is counted as another level, with a total of four levels, and each level is distinguished as follows Level 0: no pain; Level 1 (mild pain): painful but not severe, tolerable, sleep is not affected; Level 2 (moderate pain): pain is obvious, unbearable, sleep is disturbed, analgesics are required; Level 3 (severe pain): Pain is severe, unbearable, sleep is severely disturbed, analgesics are required.