You know that irritable, ragey feeling that comes after getting too few hours of sleep? The one that makes you snap at your partner over coffee, or curse out other drivers on your commute? Then you know what it’s like to be tangry.
Just like skipping meals will leave you feeling hangry, new research shows that skipping out on sleep will leave you both tired and angry (aka tangry), growing madder and madder as your terrible, horrible, no-good, very-bad day marches on.
The link between sleep loss and anger was discovered by scientists at Iowa State University. The researchers had participants either get their normal amount of sleep, or restrict their amount of shut-eye over two days. Then they exposed both groups to a handful of irritating noises and noted their reactions.
“In general, anger was substantially higher for those who were sleep-restricted,” study author Zlatan Krizan said in a press release. “We manipulated how annoying the noise was during the task, and as expected, people reported more anger when the noise was more unpleasant. When sleep was restricted, people reported even more anger, regardless of the noise.”
As humans, we tend to get used to daily frustrations, like construction sounds or a coworker’s phlegmy cough. If you’re tired, however, you’ll likely get angrier as the noise goes on. Now, the study authors are looking into whether exhaustion can cause aggression.
Unbridled anger may be one of the most visible effects of sleep loss, but it’s not the only sign you need more Zzzs. Here’s how to tell when your lack of sleep is catching up on you.
Your stomach is rumbling
You may be able to blame your sleep habits for your Taco Bell craving: Studies have tied a lack of shut-eye to an increased appetite, particularly for foods rich in fat, salt, and sugar.
Why: When you sleep for too few hours, your hormones get out of whack. Your body produces more of the hormone ghrelin, which causes hunger to spike, and less of the hormone leptin, which usually tampers down your hunger levels.
Your personal bubble shrinks
Ever feel like the world is closing in on you when you’re tired? You’re not alone.
One study found that sleepiness correlates to an increase in the physical distance you need from others.
You can’t stop sneezing
A lack of sleep can seriously screw with your immune system. Sleep deprivation has been linked to a reduced production of cytokines, a type of protein responsible for fighting infection and inflammation, and even found to reduce the efficacy of the flu shot by hindering your body’s response to the vaccine.
You keep forgetting that one girl’s name
Quick, what were you doing before you started reading this article? If you can’t remember, you might need to hit the sack a little earlier.
In a 2016 study, researchers found that five hours’ worth of sleep deprivation (aka getting three hours of sleep, rather than eight) was linked to a loss of connectivity between neurons in the region of the brain associated with memory and learning. The only solution? Getting more sleep.
How to catch more Zzzs
Of course, there’s nothing worse than being told how important sleep is, then staring at your ceiling as the minutes tick by. If falling asleep is your problem, one of the most effective fixes is creating an evening routine.
Prime your body for snoozing with a bedtime ritual. That might mean hitting the sheets at the same time every night, journaling for 10 minutes before bed, sipping some chamomile tea, or even repeating a prayer or intention. Creating a ritual will cue your brain and body to get into sleep mode–and prevent any impulsive sleep-disturbing behavior.