Breast injury
If an injury has recently occurred around your breast, it may be the cause of breast numbness. This physical trauma would affect the surrounding nerves, resulting the numbness, pain, and bruises. In most cases, these symptoms tend to disappear after a couple of days. Common causes of breast injuries include direct impact when bumping into a hard surface or during an accident, physical contacts during sports, using breast pumps, repetitive movements of your breast without supportive bra, wearing too tight clothes. Mild injuries can be treated at home by taking OTC medications, applying a cold or hot compress, or wearing a comfortable bra to support your breast. [1]