The reason why the left side of the left breast hurts when pressed is no more than the following: 1, lymph nodes under the skin, irritation produces inflammation will not only increase, redness, swelling, heat, pain, anti-inflammatory control is needed, if the lymph nodes are too large need to be surgically removed. 2, breast hyperplasia, breast hyperplasia patients under the breasts will have nodules produced by the effect of increased estrogen, before menstruation and menstruation there will be nodules touching, breast swelling, stinging, skin warmth, swelling. , tingling, warmth and swelling of the skin. If the pain is not obvious and disappears after menstruation, you don’t need to take medication, and if the pain is obvious, you can take prophylactic pills.3. Breast cancer, the lumps of breast cancer patients can be painless, and if they invade the nerves, they will show obvious pain, which requires timely surgical treatment, pathological examination, regular chemistry after surgery, and periodic rechecking.