Defending

If you sent reinforcements to the clan mate your troops that are defending him are getting attacked. So if you have 300k troops and sent 200k reinforcements to your friend, only those 200k troops will be injured or killed.

If you are not reinforcing someone and view a battle report from clan chat the bottom of the report has some confusing verbiage that can make it seem like you are being attacked. But, unless you have a reinforcement march at the clan mate being attacked your troops won’t be injured or killed.

 

and to add to that...you should recall your troops, heal them and send them back to defend. Your troops are still tied to your hospital cap, so if your hospital gets full, then yeah, your troops will start to die instead of being only injured. You can scroll down in the battle report to see information on your actual troops when you defend vs total troop loss. You just have to look further in the battle report.