There are five main possibilities for constant chest pain: first, lung cancer, which is manifested as chest tingling and may be accompanied by irritating cough or hemoptysis. Second, gastroduodenal ulcer, which is characterized by pain behind the sternum and is obviously related to eating, and may be accompanied by acid reflux and belching discomfort. Third, coronary artery disease, which is characterized by crushing pain in the anterior thoracic region with posterior back radiating pain, and the pain can be relieved by sublingual nitroglycerin. When the disease progresses to the advanced stage, it may appear as hidden pain in the breast, accompanied by nipple inversion or skin folding. Fifth, cystic hyperplasia of the breast, mostly seen in women of childbearing age, manifests as breast swelling and pain with nodule-like changes of breast enlargement, and the degree of pain is mostly related to the menstrual cycle. When the chest is always chest pain, you should go to the regular medical institutions in time to clarify the cause and targeted treatment.