If you’re middle age or older, hopefully this won’t keep you up at night: Getting less than five hours of sleep can heighten your risk of developing at least two chronic diseases.

That’s what researchers at University College in London determined after analyzing the effect of sleep duration among more than 7,000 people between the ages of 50 and 70. Not only was a lack of sleep associated with chronic diseases, it was also linked to higher death rates in those age groups.

At age 50, those who consistently slept five hours or less were 20% more likely to be diagnosed with a chronic disease such as cancer, diabetes or heart disease than those who slept at least seven hours. Following study participants 25 more years, the researchers discovered the light sleepers were 40% more likely to have two or more chronic diseases.

For the 50-year-old group, there was also a 25% greater mortality rate over their next 25 years. The researchers noted a vicious cycle: Short-sleep duration raises the risk of chronic diseases, which increases the risk of death.

The problem is pervasive, with more than half of older adults in some wealthier countries having at least two chronic diseases. That creates challenges for governments and insurers that fund health care.

The researchers said it’s important to understand how sleep habits change with age, with older people often having trouble falling asleep and staying asleep. Seven to eight hours of sleep is considered ideal.

If you have trouble sleeping, here’s a pro tip: Physical activity and exposure to light during the day can help ensure you log enough hours counting sheep.