The first thing to consider is whether the shoulder pain is related to the daily sleeping posture, because poor blood circulation due to pressure on the left arm can easily cause shoulder pain, and cold or overwork at night can also cause shoulder pain. Long-term and recurring shoulder pain needs attention, and if necessary, you can go to the hospital for consultation. 1.Left shoulder pain Frozen shoulder is a pain in the shoulder centered on the shoulder joint, which can restrict the movement of the shoulder. Aging and overexertion of the shoulder joint and the muscles around the shoulder are usually the cause of its development. Since the sensory nerves for shoulder pain and heart pain are very close to each other, both in the posterior horn of the spinal cord, problems with the heart can also reflexively cause pain in the left shoulder, such as angina pectoris and myocardial infarction. The difference between the two is that left shoulder pain caused by heart disease is mostly activity-related, occurs during activity, is paroxysmal, and is regular, and can be relieved by rest or nitroglycerin. The pain caused by frozen shoulder mostly occurs after exertion, and cannot be relieved by resting with nitroglycerin. 2. Right shoulder pain Acute gallbladder inflammation can stimulate the right phrenic nerve endings, resulting in reflex pain in the skin of the right shoulder. The phrenic nerve is composed of the 3rd to 5th cervical nerves, mainly the 4th cervical nerve, and its branches are distributed on the skin of the shoulder. When the right phrenic nerve terminal is stimulated and travels through the phrenic nerve to the 4th cervical ganglion, it causes the cerebral cortex to have the illusion that the pain is coming from the right shoulder. Therefore, when the right shoulder pain is difficult to relieve, ultrasound examination can be done first to exclude cholecystitis. If the diagnosis of cholecystitis is confirmed, anti-infection, antispasmodic and analgesic treatment can relieve the shoulder pain. 3.The more you press, the more painful it is. When you have neck and shoulder pain and your family gives you a press, you immediately feel relaxed and comfortable, but it doesn’t take long for the condition to flare up again, so you should consider other diseases. For example, neurogenic cervical spondylosis caused by nerve root edema is the most common cervical spondylosis, the acute attack of the disease should not be massage, massage, traction, otherwise it will aggravate the nerve root edema, making the condition worse. The correct approach is to first eliminate nerve root edema through systematic treatment, and then to be treated by a professional doctor with massage, traction, etc. 4.Inexplicable pain Bone metastasis of spinal malignant tumor is more common, and the patients are mostly middle-aged and elderly people aged 40~70. Because their symptoms are not specific, they are often misdiagnosed. Spinal malignant tumors invade the thoracic spine most often, followed by the lumbar, cervical and sacral spine. Pain and neurological dysfunction of the limbs is a sign of spinal tumor. The pain can be neck and shoulder pain, back pain and lumbar and leg pain depending on the tumor site, and radiates to the upper limbs, intercostal area and legs. Therefore, when there is inexplicable strong pain in the neck and shoulder, do not treat it as “frozen shoulder”, but go to hospital for CT investigation. In addition, when lung cancer compresses the brachial plexus nerve, it will also lead to shoulder pain. Unlike frozen shoulder, lung cancer has many other symptoms besides hidden pain in the chest and shoulder, such as cough and hemoptysis that cannot be cured for a long time.