What is the medical term meaning pertaining to abnormal flow of sebum and condition hardness?

The medical term meaning pertaining to abnormal flow of sebum and condition hardness is Seborrhea.

Seborrhea is a common skin condition that affects both men and women. It is caused by an overproduction of sebum, an oily substance that helps to keep skin and hair healthy. Seborrhea can cause the skin to become oily, red, and flaky, and can also lead to the development of acne.