Men who have insomnia are four times more likely to die than men who get a good night’s sleep, according to a study from the Pennsylvania State University’s College of Medicine and reported by QualityHealth.

What is insomnia? It’s the most common sleep disorder and is defined as having difficulty initiating or maintaining sleep or both.

For the study, researchers tracked the sleep habits of 1,741 randomly selected men (average age 50) and women (average age 47). Scientists followed the men for 14 years and the women for 10 years.

Researchers found that men who slept less than six hours each night were four times more likely to die than men who got more sleep. (The findings about women were inconclusive because women were underrepresented in the study and were not followed for the same time period as the men.)

In addition, findings showed that lack of sleep still influenced men’s mortality rates even when researchers took into account other factors affecting life expectancy, such as obesity, high blood pressure, diabetes and sleep apnea (a common and serious sleep disorder in which breathing repeatedly stops and starts).

What’s more, experts documented that not getting enough sleep on a regular basis can increase risk of heart disease, diabetes, anxiety and depression, which all can result in death.

“Insomnia is not just a psychological problem but has significant physical consequences,” said Edward Bixler, PhD, the study’s coauthor.

But despite these nightmarish findings, scientists say more research is needed before they can claim not getting enough ZZZs directly causes death.

Right now, what’s most important about the study, scientists agreed, is the message to both patients and physicians that insomnia isn’t harmless.

Having trouble sleeping? Click here to see some reasons why.