Holding urine for long time can damage kidneys?

No, usually, but... Holding urine to overcome inconvenience sporadically will not hurt / damage the kidneys as long as being able to to empty bladder well and comfortable with good urine flow. More on how men urinate? Go to articles in http://formefirst.com/TroublingVoiding-Men.html. On how to handle sickness? Go to articles listed in http://formefirst.com/onDealSickness.html.