And what to do about it.
Brian Byrne, a tour manager in Los Angeles, was sipping a cold brew a few years ago when he started feeling clammy. Soon, his symptoms worsened: shallow breathing, a hollow feeling in his chest and a rapid, thumping heartbeat. He went outside to get air. “At that point, I was having racing thoughts, feeling like I was having a heart attack,” he said.
This wasn’t the first time Mr. Byrne experienced a caffeine-fueled panic attack, but it was the most intense. “Drinking that coffee felt like I poured gasoline on a fire that was already smoldering,” he said. For a year after, he didn’t touch the stuff and didn’t have another serious episode.
Many people can relate to Mr. Byrne’s caffeine-related anxiety. While researchers can’t definitively say that caffeine makes you anxious, it’s linked to increased risk of anxiety among people with and without psychiatric diagnoses.
Why caffeine might make you anxious
Caffeine is a stimulant that affects the sympathetic nervous system — the part of the body responsible for your fight-or-flight response. When it’s activated, your heart rate rises and blood pressure goes up, your muscles tense, and you may start sweating.
But caffeine isn’t the only thing that arouses the nervous system. Any adrenaline-pumping activity — like exercising or riding a roller coaster — can stimulate a response.
When you’re working out or on a ride, those sensations aren’t a surprise. But the incongruity of sitting quietly at your desk while your heart is pounding, the way it might if you’ve just had some caffeine, can make some people experience that arousal as anxiety, said Joseph Trunzo, a deputy director of the School of Health and Behavioral Sciences at Bryant University. On top of that, if you subconsciously label these symptoms as anxiety, you might reinforce the effect.