Board Thread:Questions and Answers/@comment-24749544-20140505080714/@comment-18497248-20140505165020

Everyone ages differently with much more radical differences than real life. Evidenced by Unohana being over 1000 but only appearing to be in her mid-to-late 30's, and Yamamoto being over 2000 and appearing as an old man. There is no clear rate at which people age in the Soul Society, everything is either subdued or highly noticeable.