You know stress is unpleasant. Doctors caution it can also kill you. Stress causes your body to release cortisol, It prepares you to face a threat by getting your heart pumping and flooding your body with sugar to power your muscles.

That was great when the threat was the occasional hungry lion. But when the stressor is your inbox pinging every 36 seconds, the results can be ugly.

"Overexposure to cortisol and other stress hormones... can disrupt almost all your body's processes," warns the Mayo Clinic. The result is elevated risk of everything from fertility problems and depression to diabetes and heart attacks.

Maybe you already know all of this. But here's what you probably haven't realized: your phone is one of the biggest sources of long-term stress in your life, and looking at it constantly is likely shaving years off your life.

The little stress machine in your pocket

That's the message of a scary New York Times article in which Catherine Price talks to a slew of doctors worried that our collective phone addiction is literally shortening our lives.

First, Price points out that our phones are not some minor lifestyle accessory. We spend a shocking amount of time looking at them -- four hours a day on average -- and most of us wildly underestimate how much time we waste attending to our blinging gizmos. That can't be good for productivity, but it's also bad for our bodies.

"Your cortisol levels are elevated when your phone is in sight or nearby, or when you hear it or even think you hear it," University of Connecticut School of Medicine psychiatrist David Greenfield tells Price. "It's a stress response, and it feels unpleasant, and the body's natural response is to want to check the phone to make the stress go away."

We think about our phones. We feel an itch of stress. We check them. We think that will relieve the little tickle of anxiety, but instead there's usually an annoying message, undone task, or horrifying headline awaiting us. We stress more. Drip by drip over time this cycle adds up to a whole lot of stress... and a greater risk of premature death.

How to get your cortisol levels under control

If you're terrified enough by these warnings to actually do something about your phone problem, there is plenty of advice out there. Everyone from computer scientists to doctors have sensible recommendations to tame your addiction, from simple steps like turning off notifications and making your phone intentionally uglier, to slightly more involved "digital detox" programs that will put you on a healthier footing with all the tech in your life.

On top of these technical fixes, mindfulness can also help. Stanford psychologist Kelly McGonigal advises those who want to break free of tech-related stress to pay closer attention to their feelings, including the spike in anxiety when you think about your phone.  

"Surf the urge. Pay attention to what it feels like in your body and to your breathing. Think of the urge like a wave you are going to surf, and breathe through it," she recommends. "Like a wave, it will crash and dissolve. Cravings sustain themselves when your brain and body believe you are going to give in. As soon as you make a commitment not to, it begins to change how the brain is processing the craving."

Taking these steps to break the phone-stress cycle won't just help you get more done and feel better. They could actually save your life.