Left breast pain is often caused by the following reasons: 1, trauma: when the breast is violently touched or knocked, it can lead to pain, and you need to go to the hospital surgery for clarification. If the problem, you can carry out local hot compresses, physiotherapy, to relieve the symptoms of pain, some patients can also take oral pain medication. 2, breast hyperplasia: this is a common disease, is the body’s estrogen and progesterone secretion abnormalities caused by the need to go to the hospital to check the ultrasound of the mammary glands to be clear. If the disease, you can take oral medication to relieve the symptoms, such as breast quenching tablets, free pills, etc. 3, swelling in the mammary gland: both benign swelling, such as fibroids, but also malignant swelling, such as breast cancer, need to do ultrasound, molybdenum target or MRI, etc. to make clear, and if necessary, to do a puncture biopsy.