The causes of chest pain for half a month are rib fracture, acute mastitis, intercostal neuralgia, breast cancer, aortic dissection, as follows: 1. Rib fracture: there is a clear history of chest trauma, manifested by chest pain and paradoxical movement, and the pain can be significantly exacerbated by deep breathing; 2. Acute mastitis: it occurs in lactating women, and is an acute suppurative infectious disease in the breasts, clinically manifested by redness and swelling of the breasts and hot and painful pain, and a fluctuating lump is touched in the breasts in severe cases. 3. In severe cases, fluctuating lumps can be touched in the breast; 3, intercostal neuralgia: manifested as chest flaky or striated pain, aggravated by coughing; 4, breast cancer: manifested as persistent hidden pain in the breast, and hard texture and poor mobility lumps can be touched in the breast; 5, aortic coarctation: a history of high blood pressure, manifested as post-sternal tearing pain, and pain can be relieved after active antihypertensive treatment. When the breast chest pain after half a month, should promptly consult a regular hospital, clear cause of pain, and actively cooperate with the specialist treatment.