A lack of deep sleep causes damage to the brain.
A new study has found that uncontrolled sleep apnea - a condition in which people stop breathing for 10 seconds or more multiple times per night - harms the health of the brain and increases the risk of dying from various health problems.
People with severe and untreated sleep apnea who spent less time in deep slumber had more damage to the white matter of the brain than those who sleep well at night.
White matter is the tissue that forms connections between brain cells and the other parts of the nervous system. Small white spots indicate how much damage has been done when the organ is scanned.
According to the Mayo Clinic in Minnesota, for every 10 per cent decrease in time spent sleeping deeply an increase of white matter in the brain similar to the effect of being 2.3 years older is spotted.
Sleep specialist Kristen Knutson of Northwestern University said: "Their findings are consistent with the literature that indicates sleep plays an important role in maintaining brain health."