Sleeping well is vital for your long term health. If you usually sleep less than 7 hours a night, your risk of dying is 10-30% higher than that of people sleeping 7-8 hours per night, according to dozens of studies1,2. Contrary to the case with exercise, more sleep is not necessarily better. People that regularly sleep more than 9 hours are similarly at risk.
Cause or effect?
The studies do not directly show that the lack of sleep is the cause of the higher mortality rate. There are obvious examples where something causes both higher mortality and a lack or excess of sleep, such as stress, a disease or substance abuse. In such cases the amount of sleep is nevertheless still an indication that something is wrong and attempting to improve your sleep should result in addressing the root cause.
- Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies
- Sleep and mortality: a population-based 22-year follow-up study