Used in casual conversation, might sound rude or offensive in formal situations. Everyone laughed when he called himself a nutcase for forgetting his own birthday.
Pro Tip 2/3
Emotional Weight
Can be seen as insulting and hurtful if used about someone with mental health issues. I regret calling her a nutcase during our argument; it was insensitive.
Pro Tip 3/3
Cultural Sensitivity
Understanding varies by culture; some might find it humorous, others deeply offensive. After moving to the UK, I realized 'nutcase' wasn't as harsh as it was back home.