If the disease is here and the pain is in the same place, the cause of the pain is easier to determine; if the disease is here and the pain is in another place, the situation is more complicated, and this kind of pain is medically called involved pain. Dr. Liu Xiufen, chief physician of the pain clinic of Peking University Hospital, said that involved pain is related to the distribution and conduction of nerves, and the sensory nerve of the lesion is transmitted to the spinal cord and then transmitted upward or downward, and then from the distant sensory nerve. As for the distance, it can be as close as 10 cm or more, or as far as 1 meter away. Commonly associated pains include the following: Facial and neck pain: It can be caused by angina pectoris and myocardial infarction, and is often misdiagnosed as toothache and lymphadenitis. Chest pain: The pain of reflux esophagitis with cardia dystonia (cardia spasm) resembles angina pectoris, hence the name pseudo-angina pectoris or esophageal-derived chest pain. Gallstone disease and cholecystitis may not only present with chest pain similar to angina attack, but may even present with heart rhythm disturbance, which is called biliary heart syndrome. Severe intestinal distension, high diaphragm, especially in people who smoke a lot and ulcer patients can have chest pain, which is called gastrocardiac syndrome. Back pain: Patients with acute pancreatitis and about 1/4 of pancreatic cancer have back pain, which is more severe in supine position and relieved when sitting and leaning forward. Patients with penetrating ulcers, duodenal bulb and retrobulbar ulcers often have intractable back pain. In addition, cholelithiasis and chronic cholecystitis back pain are also the first symptoms and are often misdiagnosed as back muscle strain. Abdominal pain: Pneumonia at the base of the lung and diaphragmatic pleurisy disease in the chest can cause epigastric pain. This is not surprising because of their proximity to each other. The heart is slightly further away from the abdomen, but people with angina pectoris and myocardial infarction can also present with severe epigastric pain with abdominal muscle tension and even increased white blood cells. Some patients have been misdiagnosed as perforated ulcer, pancreatitis, and cholelithiasis. Although the brain hemorrhage is in the brain, diffuse pain, ulcer-like pain and abdominal pain with transient loss of consciousness can occur in the abdomen, which can be a problem caused by “distant relatives”. Upper and lower extremity pain: herniated discs and osteophytes can cause pain in the upper and lower extremities depending on the location of the lesion, which is familiar. However, inflammation of the nerves in the spine, vascular malformation, and lateral sclerosis are often misdiagnosed as osteophytes. Angina pectoris and esophageal lesions can radiate to the left and right upper extremities and even straight to the fingertips.