He gets ratty if he doesn't get enough sleep.

他要是睡眠不足动不动就发脾气。

《牛津词典》

When you get enough sleep, you won't feel sleepy.

当你睡眠充足时，你就不会感到困倦。

youdao

Is there any reason why you can't get enough sleep?

你睡眠不足有什么原因吗？

youdao

You just don't get enough sleep!

你就是会睡眠不足！

苦中有乐的学习 - SpeakingMax英语口语达人

Maybe you are more creative if you get enough sleep and spend time with your family.

FORBES: 3 Tips For Women Who Want It All: Career, Family And Freedom

Implementing three healthy family habits--eating dinner together, making sure they get enough sleep, and limiting TV--may help.

CNN: How to fight childhood obesity in 3 steps

Of course, the vast majority of people with excessive daytime sleepiness don't have hypersomnia most just don't get enough sleep at night.

WSJ: Unraveling the Riddle of Too Much Sleep