Pressing pain on the upper left chest may be related to trauma, lung disease, costochondritis, in addition, women should also consider the possibility of breast disease. 1. Trauma: when the upper left chest is traumatized, such as collision or strain, it may cause local soft tissue injury or rib fracture, which may be manifested as chest pain, chest tightness, etc., and local skin lesions or bruises can be seen locally, and local compression pain may occur. 2. Lung disease: when there is a massive lung infection, a large amount of pleural effusion or pneumothorax, there may be pressing pain. 3. Costochondritis: it can be secondary to trauma, infection, etc. It can be manifested as chest pain, mostly dull pain, hidden pain, etc. The rib cartilage in the painful area is enlarged and bulging, and the pain is obvious when pressed. 4. Breast diseases: such as breast hyperplasia, mastitis and other conditions, the upper left chest can also be manifested as pressure pain, mastitis is accompanied by fever, chills and other systemic symptoms. There are other causes of pain in the upper left chest, and it is recommended that patients seek medical attention as soon as possible to avoid delaying their condition.