scar tissue

scar tissue (uncountable)

1. (anatomy) A type of tissue found in animals containing a higher than normal amount of the protein collagen formed in a place where an injury has healed.
2. By extension, the abstract feeling of there being long-term consequences of a negative event.
   • 2010, Kevin Leman, Sheet Music: Uncovering the Secrets of Sexual Intimacy in Marriage, page 32:

     So many people's lives have many broken relationships that have left behind psychological scar tissue.

• asteriscus