diagnosing

/D AY0 AH0 G N OW1 S IH0 NG/
verb
  1. 1

    To determine which disease is causing a sick person's signs and symptoms; to find the diagnosis.

  2. 2

    (by extension) To determine the cause of a problem.

Source: https://en.wiktionary.org/wiki/diagnose, https://en.wiktionary.org/wiki/diagnosing