It's claimed sleeping longer than eight hours a night could be linked to early death.
People who stay in bed for longer than 10 hours are also more likely to die of a stroke or heart disease.
Researchers say data from 3 million people suggests those who get 10 hours are 30% more likely to die early.
However, it has also claimed those who don't get enough sleep are more at risk of getting illnesses such as heart disease.
The research has also revealed though that a lack of sleep can also be harmful to our health.