Not getting enough sleep hikes the risk of having a stroke or suffering from heart disease over the long-term, new research suggests.
Late nights and early mornings can have critical knock-on effects on health, experts from Warwick Medical School found.
Their work, published in the European Heart Journal, found sleep disruption is linked to heart attacks, strokes and cardiovascular problems, which can lead to premature death.
Professor Francesco Cappuccio said: "If you sleep less than six hours per night and have disturbed sleep you stand a 48% greater chance of developing or dying from heart disease and a 15% greater chance of developing or dying from a stroke.
"The trend for late nights and early mornings is actually a ticking time bomb for our health so you need to act now to reduce your risk of developing these life-threatening conditions."
He and Dr Michelle Miller examined evidence covering seven to 25 years. There were 470,000 people involved, spanning eight countries, including Japan, the US, Sweden and the UK.
At a chronic level, lack of sleep sparks the body to make hormones and other chemicals that boost the risk of a range of health problems, including diabetes, high blood pressure, obesity and excess cholesterol, Dr Miller said.