Hyperkeratosis

What Is It?

Published: January, 2019

Hyperkeratosis is a thickening of the outer layer of the skin. This outer layer contains a tough, protective protein called keratin.

This skin thickening is often part of the skin's normal protection against rubbing, pressure and other forms of local irritation. It causes calluses and corns on hands and feet. It can cause whitish areas inside the mouth.

To continue reading this article, you must log in.
  • Research health conditions
  • Check your symptoms
  • Prepare for a doctor's visit or test
  • Find the best treatments and procedures for you
  • Explore options for better nutrition and exercise

New subscriptions to Harvard Health Online are temporarily unavailable. Click the button below to learn about our other subscription offers.

Learn More »