When you drink too much on a night out, you might fully expect the headache, exhaustion, dry mouth and general malaise. But there’s one less discussed symptom that frequently accompanies a hangover: anxiety.
In one 2012 study, 7.4 percent of those experiencing a hangover also suffered anxiety as a symptom. Another study showed heavy drinking “lowers mood, disrupts sleep, increases anxiety” and produces “physical” and “emotional” symptoms the morning after. Research published in 2015 also revealed many social drinkers experience emotions like shame, guilt and embarrassment following a drinking episode.
Why are the worries and emotions so hard to control during a hangover? Researchers are still figuring that out.
“You’d think we would totally understand the hangover at this point, but we don’t,” said Aaron White, senior scientific adviser to the director of the National Institute on Alcohol Abuse and Alcoholism. Excessive drinking has been chronicled for centuries, even appearing in texts like the Bible, he noted.
Still, there’s plenty of speculation on why exactly you’re anxious in the aftermath of a drinking binge. Here are some leading theories:
Alcohol leads to poor sleep, triggering anxiety.
There are likely several reasons your body and mind feel so terrible, White said. Part of the problem is sleep. What you typically do when you’re out drinking, like going to bed late, sleeping in strange places and other “out of routine” behaviors, disrupts your regular sleep patterns.
“You go out drinking, you go home, you probably immediately pass out, and then you wake up four to five hours later feeling terrible,” White explained.
Alcohol can alter circadian rhythms, keep you from entering rapid eye movement sleep ― the last stage of sleep ― and lead to more bathroom trips throughout the night. And according to the Anxiety and Depression Association of America, research has shown poor sleep can trigger anxiety, and vice versa.
Alcohol disrupts the brain’s delicate balance.
According to White, your brain is always trying to maintain homeostasis ― stability ― in its processes.
“Emotionally, there’s a balance too,” he said. “You have a normal level of anxiety, a normal positive affect and so on.”
When you consume alcohol, a depressant, White said, the substance “starts to dampen brain activity.” When your drink impacts the amygdala, the area of the brain responsible for emotional responses, you may feel more relaxed and at ease ― for a while, anyway.
Eventually, the alcohol exits your system and your brain will want to regulate its functioning, all the way back to your personal baseline.
“The alcohol pulls the amygdala in one direction,” he said. “But then the alcohol wears off, your brain starts to pull back to establish its normal, and sometimes it overshoots in the opposite direction.”
So, instead of feeling chill and calm, you suddenly feel nervous and stressed. Since the amygdala is also involved in other cognitive functions, White explained, you may also suffer impaired memory and attention problems in addition to increased anxiety.
A hangover causes you to feel sick and sensitive.
In general, a hangover makes you feel ill and off-kilter.
“Research shows cytokine levels in the body change after you drink,” White said. Cytokines are the body’s immune messengers, responsible for anti-inflammatory and inflammatory responses.
“This tells us [a] hangover involves disrupting the cytokine pathways and disrupting your immune response,” White said. “And a hangover looks a lot like ‘sick behavior.’” With those next-day effects, you may experience malaise, fatigue, vomiting or mood changes, including anxiety and depression. “These sick behaviors are your brain’s way of saying to retreat and heal,” White said.
Those prone to anxiety may also be more prone to drinking in excess, especially those who feel they need alcohol to loosen up at social gatherings.
“Because alcohol has sedative properties, it leaves you feeling the opposite the next day,” said Scott Bea, a psychiatrist at the Cleveland Clinic.
With sustained use, Bea said, alcohol can lead to a drop in the levels of serotonin, the “calming hormone” that may help reduce anxiety. You’ll also experience a drop in blood sugar with the drinking, as well as dehydration.
“Those with anxiety are very sensitive to physiological changes,” he said. “When the heart rate is elevated, when the body feels weird, it can set off a panic attack.”
So what to do?
Once you feel the nerves hit during a hangover, it’s nearly futile to stop the anxiety.
“Learn mindfulness,” Bea said. “Watch your thoughts and sensations rather than react to them.” The less you try to do about the panic, the more likely it is to go away.
And don’t forget, when you’re hung over, the body is exhibiting sick behavior because the brain wants you to rest.
“Alcohol is a toxin,” White said. “It’s one we enjoy, but a toxin to the body nonetheless. ... When you feel that malaise and illness, your brain wants you to lay low. There’s little you can do except make yourself comfortable.”
Of course, if you’re prone to anxiety or experience it frequently with a hangover, sticking within “reasonable alcohol limits” is always a smart idea, Bea said. Drinking less is the best way to stop post-party panic from wrecking your day.