Can an adult grow taller or increase height naturally?

No.

You cannot physically make yourself grow taller in any natural way after you have finished growing. This typically happens in late teens or early 20's.

For more in-depth information, see the page link, further down this page, listed under Related Questions.

There are things you can do to make you look taller:

  • types of clothes
  • color of clothes
  • shoes with heels
  • good posture (NEVER slouch)