Unexplained sadness can have various causes, ranging in severity from 'worrying' to 'very serious'. Finding the true cause means ruling out or confirming each possibility – in other words, diagnosis.
Diagnosis is usually a complex process due to the sheer number of possible causes and related symptoms. In order to diagnose unexplained sadness, we could:
Do you cry or become teary/sad for no reason?
Possible responses:→ No / don't know
→ Very rarely - no more than once a year
→ Occasionally - a few times a year
→ Regularly - at least once a month
→ Often - several times a week