Pain under the left breast can cause a condition called costochondritis. When the cartilage that is located between the ribs begins to swell, costochondritis is raised. The ribs generally swell at its junction with the sternum or breastbone. Unions in this area can hurt because of costochondritis.
According to the Health System and Costochondritis.org Loyola University, this disease can cause pain in your breasts.
Before the period
Just before your menstrual period, when there are high levels of prostaglandin in the body of the woman, she can escape into the bloodstream from the uterus and have an effect on your muscles, causing pain in your breasts.
You may feel pain in the front of your chest and severe pain in your chest and in your breasts. If you touch your ribs, they are sensitive and painful.
Pain in the lower left breast can be caused by irritation of the chest wall, muscle wall thereof or because pleurisy, which is inflammation of the coverage called pleura, located between the lungs and the chest wall.
Breast pain may indicate more than costochondritis. Make an appointment with your doctor to have an official diagnosis.