This year has just finished, today is March 14, 2015, I have already treated two patients who visited our clinic due to pain and were diagnosed with bone metastasis of tumor after various tests and diagnosis. A female patient, 50 years old, with a very cheerful personality, came to see me with the results of PET/CT examination of our hospital. As soon as we met, before I asked her about the diagnosis, she said at length, “You are Prof. Zang, right? Please take a good look at me, they all said that I have advanced lung cancer, how is this possible? How can this be? I’m fine, how do I look like an advanced lung cancer patient? I thumped in my heart and scrutinized the woman in front of me carefully: her eyes were big, her facial skin was white and red, her black hair was draped over her shoulders, she was smiling when she spoke, her words were clear, there was no delirium, there was no fear, and her mental and physical appearance were normal. The first thing I asked her gently was, Are you accompanied by a family member? She said, “My daughter is outside, she cried outside, afraid of her mother’s death”, I could not help but admire her, this is another strong mother. Then she answered without asking herself, “I’m not afraid, I don’t believe I’ll get lung cancer, I don’t smoke, I don’t drink, everything is fine, how can I get lung cancer? I have to go to Beijing and Shanghai to see how can I have lung cancer?” I silently took the PET/CT test results she handed me, and from the pictures, I could already get the diagnosis clearly, it was right lung cancer, with extensive bone metastasis and liver metastasis. I asked her in the second sentence: why do you want to see a doctor? Do you have any discomfort? She replied: she had a fall in June last year, and after resting for a while, she had no pain, but the pain started again a year ago, and it hurts every day, and her walking is affected. I called her daughter in, and afterward obtained a pathologic diagnosis, and now has been treated for one cycle, the pain has been significantly reduced. How to communicate with patients and select treatment options is not the focus of today’s discussion. The second patient, also a woman, 36 years old, unmarried, was seen for chest pain in January, and the diagnosis was clearly lung adenocarcinoma pleural metastasis combined with hemorrhagic pleural fluid. Now the pleural fluid has been absorbed and the pain has disappeared. Pain is a signal of disease. The definition of pain given by the World Health Organization (WHO, 1979) is “pain is an unpleasant sensory and emotional experience caused by tissue damage or potential tissue damage”. Professor Li Jieshou, academician of the Chinese Academy of Engineering, once said, “Pain is something that everyone (except for those with abnormalities of the mind or nervous system) has felt before, only the severity of the feeling and the duration of time are different, and it is one of the symptoms of many diseases, and it is a normal physiological, or pathological change in the human body.” Acute appendicitis has pain in the lower right abdomen, severe pain, accompanied by nausea, fever, etc., which slowly disappears after the appendicitis is cured. Trauma will have pain, accompanied by bleeding, tissue damage and other local symptoms, after the trauma is cured, the pain will disappear. Acute appendicitis and pain due to trauma is a kind of acute pain, the pain itself is the main symptom of the disease, and thus the reaction is strong, and the severe cases can be accompanied by struggle, confrontation, pupil dilatation, sweating, shortness of breath, heart rate acceleration, and can start the endocrine and experiential response, which can easily attract attention, and thus get timely treatment. Neck and shoulder pain, osteoarthritis pain and other conditions are a kind of chronic pain, which is one of the most common reasons for people to visit the clinic, with an incidence rate of 20% to 45%, and requires a long period of time to visit the clinic and treatment. For example, neck and shoulder pain is a syndrome caused by cervical bones, joints, ligaments, muscles and soft tissue lesions of the shoulder joint or visceral diseases, and among the various conventional treatments, moderate physical activity is the only one with positive evidence, which needs to be adhered to over a long period of time and persistently. Cancer pain is a kind of complex pain syndrome. The pathological factors of pain in cancer are mainly due to the spread of tumor, invasion and compression of peripheral nerves as well as pain-sensitive areas such as pleura, peritoneum, periosteum and meninges, etc. This kind of pain is often abnormally intense and lasts for a long time, so cancer pain treatment should start from various aspects and take comprehensive treatment measures in order to receive better therapeutic effect. To sum up, no matter it is acute pain, chronic pain or cancer pain, for patients, pain is a signal that the organism is facing damages or diseases, so they should not endure pain without principles, and when they have unexplained pains, they should seek medical treatment as early as possible, and find out the causes of pains and give treatments actively with the help of doctors, so as to prevent their organisms from suffering from greater and more permanent damages.